Question

A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is:

Answer 1

u need to solve the following 3 equations simultaneously

let x = distance, y = speed and t = time

distance = speed x time

x = yt
x = (y+3)(t -(2/3)) t =40 mins = 2/3 hours
x = (y-2)(t+(2/3))

this looks pretty fearsome but can be done - eliminate x by subtracting second equn. from the first
then subtract third fron the first and you'll have two equns in y and t.

having found x and t plug them into x = yt to get the distance