Question

Distance between two stations x and y is 778 km. A train covers the journey from x to

y at a speed of 84 kmph and returns to x with a speed of 56 kmph. Find the average

speed of the train (in kmph ) for the whole journey.

Answer 1

The required average speed given by the formula,
Average speed =[2xy/(x+y)]km/hr.
Where,
x = 84 kmph.
y = 56 kmph.
Average speed, = [(2*84*56)/(84+56)]
= 67.2 kmph.

Answer 2

Answer:

1. average speed=2xy/x+y
2. x=56
3. y=84
4. put value in equation 1
5. 2×56×84/56+84
6. =67.2