Quantitative - Average - Questions and answers

Question:-

A train travels with a speed of 20 m/s in the first 10 minutes, goes 8.5 km in the next 10 minutes, 11 km in the next 10, 8.5 km in the next 10 and 6 km in the next 10 minutes. What is the average speed of the train in kilometer per hour for the journey described?

Option (A)

42 kmph

Option (B)

35.8 kmph

Option (C)

55.2 kmph

Option (D)

46 kmph

Correct Option:

D

Question Solution:

Find the total distance covered in each segment of 10 minutes. You will get total distance = 46 kilometers in 50 mins.

Question:-

The average weight of 5 men is decreased by 3 kg when one of them weighing 150 kg is replaced by another person. This new person is again replaced by another person whose weight is 30 kg lower than the person he replaced. What is the overall change in the average due to this dual change.

Option (A)

6 kg

Option (B)

9 kg

Option (C)

12 kg

Option (D)

15 kg

Correct Option:

B

Question Solution:

The weight of the second man is 135 and that of the third is 105. Hence, net result is a drop of 45 for 5 people. Hence, 9 kg is the drop.

Question:-

Kartik had an average of 72 on his first four math tests. After taking the next test, his average dropped to 70. How much marks he would have got in most recent test?

Option (A)

60

Option (B)

62

Option (C)

64

Option (D)

66

Correct Option:

B

Question Solution:

Total marks in first 4 tests = 72*4 = 288
Say he got ‘x’ marks on 5th tests, and his average is 70, that means
(288+x)/5 = 70
Or 288 + x = 350
Hence x = 350 – 288 = 62

Question:-

19 persons went to a hotel for a combined dinner party. 13 of them spent Rs. 79 each on their dinner and the rest spent Rs. 4 more than the average expenditure of all the 19. What was the total money spent by them.

Option (A)

1628.4

Option (B)

1531

Option (C)

1492

Option (D)

none of these

Correct Option:

D

Question Solution:

Assume x is the average expenditure of 19 people. Then, 19x = 13 * 79 + 6(x + 4).
this gives x=80.85
hence 19x= 1536.1

Question:-

What is the average of all numbers from 1 to 100 that end in 2?

Option (A)

46

Option (B)

48

Option (C)

49

Option (D)

None of these

Correct Option:

D

Question Solution:

(2+ 12+ 22+ 32+ 42+ 52+ 62+ 72+ 82+ 92)/10
Since these numbers are equally spaced, the average is the middle number. However, since there is an
even number of addends, the average will be halfway between the middle two. Halfway between 42 and 52 is 47.