221. A person walking at 5/6 of his usual speed is 40 minutes late to his office. What is his usual travel time to his office?
- A. 3 h 20 min.
- B. 3 h 15 min.
- C. 3 h 30 min.
- D. None of the above
Check answer and explanation
Answer: 3 h 20 min.
Explanation Let's say the person's usual travel time to his office is x minutes. Since he is walking at 5/6 of his usual speed, his new speed is 5/6 of his usual speed. The time taken to cover the same distance at this new speed is 6/5 of his usual time (since speed and time are inversely proportional). So, the new time taken = (6/5)x Since he is 40 minutes late, the new time taken is 40 minutes more than his usual time: (6/5)x = x + 40 Simplifying the equation: (1/5)x = 40 x = 200 minutes Converting x to hours and minutes: x = 3 hours 20 minutes