Walking towards a bus stop at 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?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 20 minutes.
Concept Used :
Speed = Distance/time.
Speed is inversely proportional to time.
Let the usual speed of Rakesh be 7x.
The speed of Rakesh after decreasing is 5x.
The ratio of usual speed to the decreased speed be 7x : 5x.
So, the ratio of the usual time to the increased time be 5x : 7x.
Given that, 7x - 5x = 10 minutes
2x = 10 minutes
x = 5 minutes
Hence the required time = 5x = 5 × 5 = 25 minutes.