Question

A boy walks 1/4th of his journey at 2 m/s and run the rest at 3 m/s - what is his average speed?​

Answer 1

Answer is 2.75 m/s average speed

Step by step

1/4 of 2 m/s + 3/4 of 3 m/s
= 11/4 or 2.75 m/s

Answer 2

See below

Step-by-step explanation:

1/4 d / 2 = time for 2 m/s

3/4d / 3 = time for 3 m/s

total distance / total time = average speed :

d / [ 1/4 d / 2 m/s + 3/4 d/ 3 m/s ] <=====simplify ( 'd' goes away)

1 / [ 1/4 / 2 + 3/4 / 3 ] = 2 2/3 m/s