Walking towards a bus stop at $\frac{5}{7}$ of his usual speed, Rakesh missed the bus by 10 minutes. What is the usual time that Rakesh takes to reach the bus stop just in time for the bus ?

25 minutes

Ratio of  ,      Usual       New

Speed             7       :     5

Time               5       :     7

ATQ ,

2R = 10 minutes

1R = 5 minutes

Usual time taken = 5R = 5 × 5 = 25 minutes