Question

A boy travels with a speed of 30kmph for 1st 1/3 journey
with a speed of 60 kmph for a maining!
for journey distance? Find average 1
speed of body​

Answer 1

Answer:

Let the distance be X.

1 / 3 x he covers using 20 km / h

Remaining = 2 / 3 km which he covers using 40 km / h

Lets take the distance x to be 1 then :

Time for the first portion will be:

T = Distance / speed

1/3 × 1/20 = 1/60 hrs

Second portion:

2 / 3 × 1/40 = 1 / 60 hrs

Average speed = total distance / total time

Total time = 2 / 60 = 1 / 30 hrs

Average speed :

1 ÷ 1 / 30

1 × 30 = 30 km / h