Aptitude Questions and Answers
Ayisha's age is 1/6th of her father's age. Ayisha's father's age will be twice the age of Shankar's age after 10 years. If Shankar's eighth birthday was celebrated two years before, then what is Ayisha 's present age.?
Consider Ayisha's present age = x
Then her father's age = 6x
Given that Ayisha 's father's age will be twice the age of Shankar's age after 10 years
=> Shankar's age after 10 years = `1/2`(6x + 10) = 3x + 5
Also given that Shankar's eight birthdays was celebrated two years before
So his current age is 8 + 2 = 10 years old
=> Shankar's age after 10 years = 10 + 10 = 20
=> 3x + 5 = 20
=> x = 5
Therefore, Ayisha 's present age = 5 years
My brother is 3 years elder to me. My father was 28 years of age when my sister was born while my mother was 26 years of age when I was born. If my sister was 4 years of age when my brother was born, then what was the age my father when my brother was born?
Let my age = x
Then,
My brother's age = x + 3
My mother's age = x + 26
My sister's age = (x + 3) + 4 = x + 7
My father's age = (x + 7) + 28 = x + 35
=> age my father when my brother was born = x + 35 – (x + 3) = 32
A is as much younger than B as he is older than C. If the sum of the ages of B and C is 50 years, what is exactly the difference between B and A's age?
Age of C < Age of A < Age of B
Given that sum of the ages of B and C is 50 years.
Let's take B's age = x and C's age = 50-x
Now we need to find out B's age – A's age. But we cannot find out this with the given data.
Sobha's father was 38 years of age when she was born while her mother was 36 years old when her brother four years younger to her was born. What is the difference between the ages of her parents?
Let Sobha's age = x and her brother's age = x-4
Sobha's father's age = x + 38
Sobha's mother's age = (x - 4) + 36
=> Sobha's father's age - Sobha's mother's age
= (x + 38) – [(x - 4) + 36]
= x + 38 – x + 4 – 36
= 6
An error 2% in excess is made while measuring the side of a square. What is the percentage of error in the calculated area of the square?
Error = 2% while measuring the side of a square.
Let the correct value of the side of the square = 100
Then the measured value = 100 + (2% of 100) = 100 +2 = 102 (∵ error 2% in excess)
Correct Value of the area of the square = 100 × 100 = 10000
Calculated Value of the area of the square = 102 × 102 = 10404
Error = 10404 - 10000 = 404
Percentage Error=4.04%
ErrorActual Value×100=40410000×100=4.04%
A towel, when bleached, lost 20% of its length and 10% of its breadth. What is the percentage of decrease in area?
Solution 1:
Let original length = 100 and original breadth = 100
Then original area = 100 × 100 = 10000
Lost 20% of length
=> New length = Original length - (20% of Original Length)
100- (20% of 100) = 100-20 = 80
Lost 10% of breadth
=> New breadth= Original breadth - (10% of original breadth)
= 100 - (10% of 100) = 100-10 = 90
New area = 80 × 90 = 7200
Decrease in area
= Original Area - New Area
= 10000 - 7200 = 2800
Percentage of decrease in area = `(2800/10000) * 100 = 28%`
The length of a room is 5.5 m and width is 3.75 m. What is the cost of paying the floor by slabs at the rate of Rs. 800 per sq. metre.
Area = 5.5 × 3.75 sq. metre.
Cost for 1 sq. metre. = Rs. 800
Hence total cost = 5.5 × 3.75 × 800 = 5.5 × 3000 = Rs. 16500
The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and breadth is increased by 5 cm, the area of the rectangle is increased by 75 sq.cm. What is the length of the rectangle?
Let breadth = x cm
Then length = 2x cm
Area = lb = x × 2x = 2x2
New length = (2x - 5)
New breadth = (x + 5)
New Area = lb = (2x - 5)(x + 5)
But given that new area = initial area + 75 sq.cm.
=> (2x - 5)(x + 5) = 2x2 + 75
=> 2x2 + 10x - 5x - 25 = 2x2 + 75
=> 5x - 25 = 75
=> 5x = 75 + 25 = 100
=> x = 1005 = 20 cm
Length = 2x = 2 × 20 = 40cm
If the difference between the length and breadth of a rectangle is 23 m and its perimeter is 206 m, what is its area?
l - b = 23 ....(Equation 1)
perimeter = 2(l + b) = 206
=> l + b = 103 ....(Equation 2)
(Equation 1) + (Equation 2) => 2l = 23 + 103 = 126
=> l = 1262 = 63 metre
Substituting this value of l in (Equation 1), we get
63 - b = 23
=> b = 63 - 23 = 40 metre
Area = lb = 63 × 40 = 2520 m2
What is the least number of squares tiles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad?
l = 15 m 17 cm = 1517 cm
b = 9 m 2 cm = 902 cm
Area = 1517 × 902 cm2
Now we need to find out HCF(Highest Common Factor) of 1517 and 902.
Hence, HCF of 1517 and 902 = 41
Hence, side length of largest square tile we can take = 41 cm
Area of each square tile = 41 × 41 `"cm"^2`
Number of tiles required = `(1517 * 902)/(41 * 41) = 37 * 22 = 814`
