Question

A man reaches his office from his residence in 10minutes at the rate of 6km per hour.How long will he take if he walks at the rate of 8Km per hour

Answer 1

The time taken is inversely proportional to the speed

t = k/v
if t = 10, v = 6
10 = k/6
k = 60

when v = 8
t = 60/8 = 7.5 minutes

Answer 2

4/3 the speed means 3/4 the time: 7.5 min.