Question

When a man walks at 9/11 of its usual speed then he is late by 1 hour 45 minutes. Find the correct time taken by the man at its usual speed?
1. 7.875 hours
2. 7.075 hours
3. 6.875 hours
4. 6.075 hours

Answer 1

Correct Answer - Option 1 : 7.875 hours

Given:

When the speed of man is 9/11 of its usual speed then he is late by 1 hr 45 minute.

Formula/Concept used:

Time and speed are inversely proportional to each other

Time ∝ 1/speed

Calculation:

When the speed of man is 9/11 of his actual speed then the time taken by him will be 11/9

∵ Speed and time are inversely proportional to each other

Let the usual time taken by man is t

∴ (11/9)t – t = 7/4 hours

⇒ t = 7.875 hours

∴ The usual time taken by man is 7.875 hours