Average

1

Distance between two stations A and B is 778 km. A train covers the journey from A to B at 84 km per hour and returns back to A with  a uniform speed of 56 km per hour. Find the average speed of the train during the whole journey.

A. 65 km/hr
B. 67.2 km/hr
C. 70 km/hr
D. 72 km/hr

2

A batsman makes a score of 87 runs in the 17 th inning and thus increases his average by 3 . Find his average after 17th inning.

A. 33
B. 36
C. 39
D. 41

3

There were 35 students in a hostel. Due to the admission of 7 new students the expenses of the mess were increased by Rs. 42 per day while the average expenditure per head diminished by Re. 1 What was the original expenditure of the mess ?

A. Rs. 420
B. Rs. 450
C. Rs. 500
D. Rs. 520

4

The average weight of 10 oarsmen in a boat is increased  by 1.8 kg When one of the crew, who weights 53 kg is replaced by a new man. Find the weight of the new man .

A. 68 kg
B. 70 kg
C. 71 kg
D. 73 kg

5

The average age of a class of 39 students is 15 years . If the age of the teacher be included, then the average increases by 3 months. Find the age of he teacher..

A. 35 years
B. 29 years
C. 28 years
D. 25 years