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

The Correct Option is B

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