60+ Lufthansa Technik Services India Interview Questions and Answers

The ball costs Rs.5.

• Let's assume the cost of the ball as x.

• According to the given information, the cost of the bat is Rs.100 more than the ball, so it would be x + 100.

• The total cost of the bat and ball together is Rs.110, so we can set up the equation x + (x + 100) = 110.

• Simplifying the equation, we get 2x + 100 = 110.

• Subtracting 100 from both sides, we have 2x = 10.

• Dividing both sides by 2, we find x = 5.

• Therefore, the ball costs Rs.5.

To calculate the number of Paan and Beedi shops in Mumbai in 3 days, I would use a combination of data collection methods and statistical estimation.

• Collect data from government records, trade associations, and local authorities

• Conduct surveys and interviews with shop owners and residents

• Utilize satellite imagery and mapping technology to identify and count shops

• Apply statistical sampling techniques to estimate the total number of shops

• Validate the results through cross-refer...read more

Market research focuses on the overall market and its trends, while marketing research focuses on specific marketing strategies and tactics.

• Market research is broader in scope and looks at the overall market, including customer behavior, market size, and competition.

• Marketing research is more specific and focuses on gathering data and insights to support marketing strategies and tactics.

• Market research helps in identifying market opportunities and potential target segments.

• Ma...read more

Answering questions related to data science concepts and techniques.

• Recall is the ratio of correctly predicted positive observations to the total actual positives. Precision is the ratio of correctly predicted positive observations to the total predicted positives.

• To reduce variance in an ensemble model, techniques like bagging, boosting, and stacking can be used. Bagging involves training multiple models on different subsets of the data and averaging their predictions. Boost...read more

There are various types of research, including descriptive, exploratory, experimental, and correlational research.

• Descriptive research aims to describe and analyze a phenomenon or population.

• Exploratory research is conducted to gain insights and understanding of a topic.

• Experimental research involves manipulating variables to determine cause and effect relationships.

• Correlational research examines the relationship between variables without manipulating them.

• Other types of res...read more

The extended 3 Ps of marketing are People, Process, and Physical Evidence. They were made to address the unique challenges of service-based industries.

• People: Refers to the employees and customers involved in the service delivery process. It emphasizes the importance of customer service and employee training.

• Process: Focuses on the procedures and systems used to deliver the service. It aims to ensure efficiency, consistency, and quality in service delivery.

• Physical Evidence: ...read more

Launching a new product involves several steps, from ideation to market launch.

• Conduct market research to identify customer needs and preferences

• Develop a product concept and create a prototype

• Test the product with focus groups and make necessary adjustments

• Create a marketing plan and determine pricing strategy

• Launch the product and monitor sales and customer feedback

• Make any necessary improvements or adjustments based on feedback

• Continue to promote and market the product to ...read more

Remove duplicates from list b, keep elements not in list a, and sort in ascending order.

• Create a set from list b to remove duplicates

• Use list comprehension to keep elements not in list a

• Sort the final list in ascending order

Random sampling error refers to the discrepancy between the characteristics of a sample and the characteristics of the population it represents.

• Random sampling error occurs when the sample selected for a study does not accurately represent the entire population.

• It is a result of chance variations in the selection of the sample.

• Random sampling error can lead to biased or inaccurate results.

• For example, if a survey about voting preferences is conducted by randomly selecting par...read more

Primary research is original research conducted by the researcher, while secondary research is based on existing research.

• Primary research involves collecting new data through surveys, interviews, experiments, etc.

• Secondary research involves analyzing existing data from sources like books, journals, websites, etc.

• Primary research is more time-consuming and expensive than secondary research.

• Secondary research is useful for gaining background knowledge and identifying research ...read more

Adjusted R-square, F-test, T-test are important statistical measures to evaluate the accuracy and significance of a regression model.

• Adjusted R-square measures the proportion of variation in the dependent variable that is explained by the independent variables in the model.

• F-test is used to test the overall significance of the model by comparing the variation explained by the model to the variation not explained by the model.

• T-test is used to test the significance of individu...read more

Sampling techniques are methods used to select a subset of individuals or items from a larger population for research or analysis.

• Random sampling: Each member of the population has an equal chance of being selected.

• Stratified sampling: Dividing the population into subgroups and selecting samples from each subgroup.

• Cluster sampling: Dividing the population into clusters and randomly selecting entire clusters for sampling.

• Systematic sampling: Selecting every nth individual from...read more

Market research involves gathering and analyzing information about a target market to make informed business decisions.

• Identify research objectives and target audience

• Choose research methods (surveys, focus groups, etc.)

• Collect and analyze data

• Draw conclusions and make recommendations

• Continuously monitor and update research

• Example: Conducting a survey to determine customer satisfaction with a product

• Example: Analyzing sales data to identify trends in a particular market

• Exampl...read more

There are approximately 50-60 traffic signals between Aurangabad and Pune.

• Consider the distance between Aurangabad and Pune is around 235 km.

• Assuming an average distance of 4 km between two signals, there would be around 58-59 signals.

• However, the number may vary based on the route taken and the traffic density.

• Also, the number of signals may have increased or decreased over time due to road development projects.

• Hence, the estimate may not be accurate and should be taken as a...read more

Marketing Mix Modeling is a statistical analysis tool used to measure the impact of marketing activities on sales and customer behavior.

• Marketing Mix Modeling helps businesses understand the effectiveness of their marketing strategies.

• It involves analyzing various marketing variables such as price, promotion, product, and place.

• By quantifying the impact of each variable, companies can optimize their marketing efforts.

• For example, a company can use Marketing Mix Modeling to de...read more

Setting up a master data set involves identifying data sources, cleansing data, defining data attributes, and establishing data governance.

• Identify all relevant data sources that will be included in the master data set

• Cleanse the data to ensure accuracy and consistency

• Define data attributes such as data types, formats, and relationships

• Establish data governance policies and procedures to maintain data quality and integrity

I am currently using Colgate toothpaste, Dove toilet soap, and Durex condoms for personal hygiene.

• Toothpaste: Colgate

• Toilet soap: Dove

• Condoms: Durex

Check if string s is a subsequence of string t.

• Iterate through both strings using two pointers.

• Compare characters of s and t, moving pointer in t only if characters match.

• If all characters of s are found in t in order, return true.

• Example: s = 'abc', t = 'ahbgdc' => true

Count the number of light poles in a city

• Use satellite imagery to identify and count light poles

• Conduct a physical survey of the city and count the number of light poles

• Request data from the city's public works department or utility company

• Use machine learning algorithms to identify and count light poles in images

Multicollinearity can lead to inaccurate and unstable regression coefficients.

• It can make it difficult to determine the effect of individual predictors on the outcome variable.

• It can lead to inflated standard errors and p-values, making some predictors appear insignificant.

• It can cause the model to be less reliable and less accurate in making predictions.

• It can also make the model sensitive to small changes in the data.

• For example, if both height and weight are used as predic...read more

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications.

• Kubernetes is used to manage containerized applications across multiple hosts.

• It provides features like automatic scaling, self-healing, and rolling updates.

• To get a list of all pods, use the command 'kubectl get pods'.

• To delete multiple pods in one command line, use the command 'kubectl delete pods ...'.

Co-efficient, Regression, and Linear Regression are statistical concepts used to analyze the relationship between variables.

• Co-efficient is a measure of the strength and direction of the relationship between two variables.

• Regression is a statistical method used to model the relationship between a dependent variable and one or more independent variables.

• Linear Regression is a type of regression analysis where the relationship between the dependent variable and independent vari...read more

Fail fast iterator throws ConcurrentModificationException if the collection is modified while iterating. Fail safe iterator does not throw exception but works on clone of collection.

• Fail fast iterator checks for modification during iteration and throws ConcurrentModificationException if found.

• Fail safe iterator works on clone of collection and does not throw exception if collection is modified.

• Example: ArrayList iterator is fail fast, while ConcurrentHashMap iterator is fail ...read more

S/4 HANA implementation involves migrating business processes to SAP's latest ERP system for improved efficiency and real-time analytics.

• Data migration from legacy systems to S/4 HANA

• Business process reengineering to align with S/4 HANA functionalities

• Customization and configuration of S/4 HANA modules

• Training employees on using the new system effectively

• Testing and validation of the implemented solution

BinarySearch algorithm using Recursion finds the target element in a sorted array by dividing the array in half at each step.

• Divide the array in half and compare the target element with the middle element

• If the target element is smaller, search the left half recursively

• If the target element is larger, search the right half recursively

• Repeat until the target element is found or the array is empty

Use the DISTINCT keyword in SQL to remove duplicates from a table.

• Use the SELECT DISTINCT statement to retrieve unique rows from the table.

• Identify the columns that should be used to determine uniqueness.

• Example: SELECT DISTINCT column1, column2 FROM tab1;

It is difficult to provide an exact number without specific data, but an estimate can be made based on population size, average household size, and consumption habits.

• Estimate based on population size of the city

• Consider average household size and consumption habits

• Look at sales data from local stores or manufacturers for a rough estimate

Use SQL query with ORDER BY and LIMIT to find the nth highest salary of an employee.

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT to specify the nth highest salary

• Example: SELECT salary FROM employees ORDER BY salary DESC LIMIT n-1, 1

A dirty read occurs when a transaction reads data that has been modified but not yet committed by another transaction.

• Dirty reads can lead to inconsistencies, as the data may change before the first transaction is committed.

• For example, if Transaction A updates a record but hasn't committed yet, and Transaction B reads that record, Transaction B sees uncommitted data.

• If Transaction A rolls back, Transaction B will have read data that never actually existed in the database.

• Dir...read more

API for Instagram application to interact with user data and DB schema to store user information and posts.

• API endpoints for user authentication, posting photos, liking photos, following users, etc.

• DB schema with tables for users, posts, comments, likes, followers, etc.

• Example API endpoint: /users/{userId}/posts to retrieve all posts by a specific user.

• Example DB schema: Users table with columns for username, email, profile picture, etc.

A model's fit is determined by evaluating how well it performs in comparison to the data it was trained on.

• Evaluate the model's performance on a test dataset

• Compare the model's predicted values to the actual values

• Use metrics such as accuracy, precision, recall, and F1 score to assess the model's performance

• Consider the model's ability to generalize to new data

• Iteratively adjust the model's parameters to improve its fit

NodePort, Ingress, and LoadBalancer are Kubernetes services used for exposing applications externally.

• NodePort is a service that exposes an application on a static port on each node in the cluster.

• Ingress is a service that exposes HTTP and HTTPS routes from outside the cluster to services within the cluster.

• LoadBalancer is a service that exposes an application externally using a cloud provider's load balancer.

• NodePort and LoadBalancer services can be used with TCP and UDP pro...read more

Collection efficiency refers to the percentage of outstanding debts that a company is able to collect.

• It measures the effectiveness of a company's debt collection efforts.

• A higher collection efficiency indicates better management of accounts receivable.

• Collection efficiency can be calculated by dividing the amount collected by the amount outstanding.

• For example, if a company has $100,000 in outstanding debts and is able to collect $90,000, its collection efficiency would be 9...read more

Calculate average user login time based on clickstream data with 30 min session in Spark

• Filter clickstream data to include only login events

• Calculate session duration by grouping events within 30 min window

• Calculate average session duration per user

Use dropDuplicates() function in pyspark to remove duplicate rows based on primary key.

• Use dropDuplicates() function on the DataFrame with the primary key column specified.

• Specify the subset parameter in dropDuplicates() to specify the primary key column.

• Example: df.dropDuplicates(['primary_key_column'])

Creating a DataFrame from two lists in Python.

• Import the pandas library

• Create two lists of data

• Use pd.DataFrame() to create a DataFrame from the two lists

Event capturing and event bubbling are two phases of event propagation in the DOM.

• Event capturing involves the event starting from the top of the DOM tree and trickling down to the target element.

• Event bubbling involves the event starting at the target element and bubbling up the DOM tree.

• Event capturing is executed first, followed by event bubbling.

• Event.stopPropagation() can be used to stop event propagation.

• Understanding event capturing and bubbling is important for managi...read more

I test my Django apps using automated testing tools and manual testing methods.

• I use Django's built-in testing framework to write unit tests for individual components of the app.

• I also use tools like pytest and Selenium for automated testing of the app's functionality.

• I perform manual testing to ensure the app works as expected in real-world scenarios.

• I use tools like Django Debug Toolbar to identify and fix any performance issues in the app.

Managing multiple teams on multiple technologies requires effective communication, delegation, and prioritization.

• Establish clear communication channels and expectations for each team

• Delegate tasks based on team strengths and workload

• Prioritize tasks and projects based on business needs and deadlines

• Regularly check in with each team to ensure progress and address any issues

• Encourage collaboration and knowledge sharing between teams

• Provide necessary resources and support for e...read more

The Fifa method for petrol price fluctuation involves monitoring and adjusting prices based on market conditions.

• Fifa method involves closely monitoring market trends and adjusting petrol prices accordingly

• It may involve setting a base price and making adjustments based on factors like crude oil prices, demand, and competition

• This method aims to ensure competitive pricing while also maximizing profits for the company

• Example: If crude oil prices increase, the company may raise...read more

A bloom filter in HBase is a data structure used to test whether a given element is a member of a set.

• Bloom filters are used to reduce the number of disk reads in HBase by quickly determining if a row may exist in a table.

• They are implemented as a compact array of bits, with multiple hash functions used to map elements to bits.

• Bloom filters can produce false positives but not false negatives, making them useful for pre-filtering data before more expensive operations.

DSO stands for Days Sales Outstanding, a metric used to measure the average number of days it takes for a company to collect payment after a sale.

• DSO is calculated by dividing accounts receivable by total credit sales and multiplying the result by the number of days in the period being measured.

• A high DSO can indicate that a company is having trouble collecting payments from customers, while a low DSO can indicate that a company has efficient collections processes.

• For example...read more

Random Forest is an ensemble learning method that builds multiple decision trees and merges them together to get a more accurate and stable prediction.

• Random Forest is a popular machine learning model used for classification and regression tasks.

• It works by creating multiple decision trees during training and outputs the mode of the classes for classification or the average prediction for regression.

• Random Forest is robust to overfitting and noisy data, and it can handle larg...read more

Design patterns are reusable solutions to common software design problems, promoting best practices and improving code maintainability.

• Creational patterns (e.g., Singleton, Factory Method) manage object creation.

• Structural patterns (e.g., Adapter, Composite) deal with object composition.

• Behavioral patterns (e.g., Observer, Strategy) focus on communication between objects.

• Design patterns help in code reusability and scalability.

Find the minimum element in a rotated sorted array.

• Perform binary search to find the pivot point where the array is rotated.

• Compare the element at pivot point to the first element to determine which half to search for the minimum.

• Continue binary search in the appropriate half to find the minimum element.

Use Stream APIs to count number of characters in a string

• Use the chars() method to convert the string to a stream of characters

• Use the count() method to count the number of characters in the stream

Types of joins in SQL include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN: Returns rows when there is at least one match in both tables.

• LEFT JOIN: Returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN: Returns all rows from the right table and the matched rows from the left table.

• FULL JOIN: Returns rows when there is a match in one of the tables.

Design a data pipeline for an e-commerce website.

• Extract data from website databases, such as product information, customer details, and order history.

• Transform the data by cleaning, filtering, and aggregating it to make it usable for analysis.

• Load the processed data into a data warehouse or data lake for storage and further analysis.

• Implement data pipelines using tools like Apache Kafka, Apache Spark, or AWS Glue.

• Monitor the data pipeline for errors and performance issues to...read more

Merge sort is a divide and conquer algorithm that recursively divides the input array into smaller subarrays, sorts them, and then merges them back together.

• Divide the input list into two halves

• Recursively apply merge sort to each half

• Merge the sorted halves back together

Design ETL process to ensure high data quality by implementing data validation, cleansing, and transformation steps.

• Identify data sources and define data extraction methods

• Implement data validation checks to ensure accuracy and completeness

• Perform data cleansing to remove duplicates, errors, and inconsistencies

• Transform data into a consistent format for analysis and reporting

• Utilize tools like Apache NiFi, Talend, or Informatica for ETL processes

Code to convert number into string

• Use a built-in function like str() in Python to convert a number into a string

• In JavaScript, you can use the toString() method to convert a number into a string

• In Java, you can use Integer.toString() to convert an integer into a string

pip is a package manager for Python that allows you to install and manage libraries and dependencies.

• pip is used to install Python packages from the Python Package Index (PyPI)

• It can also be used to uninstall packages, upgrade packages, and list installed packages

• Example: 'pip install numpy' installs the numpy package

A Pure component is a component in React that does not have any state or lifecycle methods, resulting in improved performance.

• Pure components are used to prevent unnecessary re-renders in React applications.

• Pure components implement shouldComponentUpdate method with shallow comparison of props and state.

• Examples of Pure components include functional components and class components that extend PureComponent class.

Sanction refers to a penalty or punishment imposed on an individual, organization, or country for violating a law or regulation.

• Sanctions can include economic restrictions, trade embargoes, travel bans, or asset freezes.

• They are often used by governments or international organizations to enforce compliance with laws or policies.

• Examples of sanctions include the United Nations sanctions against North Korea for its nuclear weapons program, or the US sanctions against Iran for i...read more

Count the number of vowels in a given string.

• Iterate through each character in the string and check if it is a vowel (a, e, i, o, u).

• Increment a counter for each vowel found.

• Return the total count of vowels in the string.

Merging and unmerging cells in Excel and using VLOOKUP function.

• To merge cells, select the cells and click on the 'Merge & Center' button in the Home tab.

• To unmerge cells, select the merged cell and click on the 'Merge & Center' button again.

• VLOOKUP function is used to search for a value in a table and return a corresponding value from another column.

• Syntax: =VLOOKUP(lookup_value, table_array, col_index_num, [range_lookup])

• Example: =VLOOKUP(A2, B2:C10, 2, FALSE) will search f...read more

I address escalation by remaining calm, listening actively, finding common ground, and seeking solutions collaboratively.

• Remain calm and composed during the escalation

• Listen actively to understand the root cause of the issue

• Find common ground with the parties involved

• Seek solutions collaboratively to resolve the escalation

A computer is an electronic device that can perform various tasks by executing instructions given to it.

• A computer consists of hardware components such as CPU, memory, and storage devices.

• It runs on an operating system and can execute software applications.

• Computers can be used for various purposes such as gaming, programming, and data analysis.

• Examples of computers include desktops, laptops, tablets, and smartphones.

SAP HANA DB is an in-memory database management system developed by SAP.

• In-memory database system that stores data in RAM for faster processing

• Allows real-time data processing and analytics

• Supports both OLAP and OLTP workloads

• Used for various applications like data warehousing, CRM, ERP, etc.

Coding threads with RTOS involves creating and managing multiple threads in real-time operating systems.

• Understand the RTOS scheduling algorithm to prioritize threads.

• Use synchronization mechanisms like semaphores and mutexes to avoid race conditions.

• Implement thread-safe data structures to share data between threads.

• Consider the stack size and priority of each thread to prevent stack overflow and ensure timely execution.