Question

A train with a speed of 40km/hr while going and return back along the same path with a speed of 60 km/hr. What is the average speed of train

Answer 1

Answer:

48km/hr

Explanation:

hey.....mam

the formula of same distance for two interval is

2×V1×V2÷ V1+V2=?

2×40×60÷ 40+60=?

4800÷100= 48

your answer is 48km/hr

Answer 2

Answer:

48 km/hr

Explanation:

Let the distance between those end points be d.

When going:

= > speed = distance/time

= > 40 = d/time

= > time = d/40

When returning:

= > speed = distance/time

= > 60 = d/time

= > time = d/60

Average speed = (total distance)/( total time)

= > Average speed = $\frac{d+d}{\frac{d}{40}+\frac{d}{60}}$

= > Average speed = $\frac{d(1+1)}{d(\frac{1}{40}+\frac{1}{60})}$

= > Average speed = $\frac{2}{\frac{40+60}{60*40}}$

= > Average speed = (2*60*40)/(60+40)

= > Average speed = 2*6*4 = 48 km/hr