Question

How to solve questions in which uniform speed is 9 kmph in 10 minutes. After 20 minutes the average speed is 12 kmph. Find the speed of a boy.

Answer 1

hello !
its quite simple
we hav to calculate here the speed of a boy so we need to calculate average speed of the boy that is Average speed= total Distance/total timr
= V= 9+12/0.5
=21/0.5
=42km/h.
( here we divide total time 30mint with 60;in order to convert it in the km/h).