Question

LUGELIU NU. TVO
A man travelled from his house to market on a straight road at 10 km/h and immediately returned to house at 15 km/h. Average
speed of the man is
(A) 12.5 km/h
(B) 6 km/h
(C) 12 km/h
(D) 13 km/h​

Answer 1

Explanation:

Average speed =

totaltime

totaldistance

Time taken to go to the market =

speed

distance

=

5

2.5

hour=

2

1

hours=30 minutes

Time taken to return back =

speed

distance

=

7.5

2.5

hour=1/3hours=20 minutes

Distance travelled in 10 minutes while returning back=

60

10

×7.5=1.25km ( Speed is constant at 7.5 km/hr )

Hence Distance traveled in 40 minutes(30 mins towards the market and 10 mins towards home) =2.5+1.25=3.75km

So average speed in 0 to 40 minutes =

60

40

hr

3.75km

=

8

45

km/hr

Answer 2

Answer:

The answer is a option D