Question

If I travelled at 3/4th of my average speed and reached 25 minutes late, what is the time that I usually take to reach my destination?

• A. 50 miin
• B. 75 min
• C. 100 min
• D. 25 min

Answer 1

The correct option is B 75 min

Since, the current speed is ${\frac{3}{4}}^{th}$ the average speed, we can take the current speed as $3km/hr$ and the average speed as $4km/hr$ so that the ratio of the speeds is $3:4$.

As the distance covered is same in both the cases, so the time taken will be in the ratio $4:3$ (in the reverse ratio of speeds).

It means that if today, I took $4$ minutes then on an average I take $3$ minutes i.e. I am one minute late.

Now apply simple chain rule that, if I am late for $1$ minute, the usual time taken is $3$ minutes and if I am $25$ minutes late, the normal time taken will be $25\times 3=75$ minutes.