Question

Walking at $\frac{3}{4}$ of his usual pace, a man reaches his office 20 minutes late. Find his usual time.

• A. 2 hrs
• B. 1 hrs
• C. 3 hrs
• D. 4 hrs

Answer 1

Answer: (B)

1 hrs

Answer 2

Let's Assume the usual time take be $t$ mins and usual speed be 4 $\frac{m}{min}$

So his new speed = $\frac{3}{4} × 4 = 3 \frac{m}{min}$ and new time will be $(t + 20\ min)$

As we know that, Speed is inversely proportional to time so,

$\frac{4}{3} = \frac{t+ 20}{t}$

On simplifying we get,

$4t = 3t + 60$

$t = 60$ mins which us equal to 1 hour

The correct option is (B): 1 hrs