Question

A man has hurt his leg and is walking at 3/4th of the speed, he reaches his office late by 90 minutes. What is the usual time?

Answer 1

let the usual speed of man=x

his new speed=3x/4

let time taken =t

therefore he reached office= t+3/2

but the distance in both the case is same

thus xt=3x/4×(t+3/2)

on solving we get

t=9/2 hours

or 270 minutes