Question

By walking at $\frac{3}{4}$ th of his usual speed, a man reaches office 20 minutes later than usual. How much time does he usually take?

• A. 30 min
• B. 60 min
• C. 70 min
• D. 50 min

Answer 1

The correct option is (B) 60 min

Let the distance between the home and office be D, the usual velocity of the man is V, and the usual time be t.

According to the question if the velocity becomes $\frac{3V}{4}$ then the time taken becomes (T+20)min.

We can say that in both the cases the distance traveled will be equal

So,

$\frac{3V}{4}\times (T+20)=V\times T$

After solving the above equation

We get,

T = 60 min.

Hence the usual time taken by the man is 60 min.