Aptitude Questions and Answers

Showing 111 - 117 of 117 questions

111

A motorist covers a distance of 39km in 45min by moving at a speed of x kmph for the first 15min, then moving at double the speed for the next 20 min, and then again moving at his original speed for the rest of the journey. Find x.?

36km/hr.

35km/hr.

37km/hr.

34km/hr.

correct answer a

Answer : 1.

Total distance = 39 km
Total time = 45 min
D = S*T
`x * 15/60 + 2x * 20/60 + x * 10/60 = 39 km `
x = 36 kmph

112

A & B are two towns. A person covers the distance from A to B on cycle at 17kmph and returns to A by a boat running at a uniform speed of 8kmph. His average speed for the whole journey is?

10.88kmph.

10.99kmph.

10kmph.

12.33kmph.

correct answer a

Answer : 1.

When same distance is covered with different speeds, then the average speed = `(2 * x * y) / (x + y)` = 10.88kmph

113

A car covers 4 successive 3km stretches at speed of 10kmph, 20kmph, 30kmph & 60kmph resp. Its average speed is?

20kmph.

30kmph.

25kmph.

27kmph.

correct answer a

Average speed = total distance / total time
total distance = 4 * 3 = 12 km
total time = `3/10 + 3/20 + 3/30 + 3/60`
= `36/60` hr
speed =`12/(36 / 60)` = 20 kmph

114

if it takes 60 seconds to complete one round around the clock what would be the time required to complete 1200 rounds of the same clock

1200 minutes

3 hours

42000 secs

45000 secs

correct answer a

1 round takes 60 seconds.

1200 rounds will take ? seconds.

? = 1200 * 60 seconds = 72000 seconds.

Not in option. So we check for minutes.

`(1200 * 60) / 60 = 1200 min`