Question

A bus cover half distance away speed V and leaning half at speed V1 for 1/3time and V2 for 2/3 time find average speed

Answer 1

Answer:

2/ (1/V + 3/(V1 + 2V2))

2V (V1 + 2V2) / ( V1 + 2V2 + 3V)

Explanation:

Assume that Total distance is 2D

Half distance=D

Time taken in first half = D/V

For other half D, let T=1/3 time

D= V1*T + V2*2T

D= T(V1+2V2)

T= D/V1+2V2

Total distance=2D

Total time = D/V + D/(V1+2V2)

Average speed = Total Distance/ Total time

= 2D/[D(1/V + 1/ (V1+ V2) ) ]

= 2/(1/V+1/(V1+V2) )

Required Answer = 2[V(V1+V2) ]/(V1+V2+V)