Walking at the rate of 4km/ph a man covers a certain distance in 2 hours and 45 mins. Running at a speed of 16.5 kmph, the man will cover the same distance in
A. 40 min B. 45 min C. 100 min D. 41 min. 15 sec
Correct Answer: A
Explanation
To find the time it takes for the man to cover the same distance running at 16.5 km/h, follow these steps:
1. Calculate the Distance: - The man's walking speed is 4 km/h, and he covers the distance in 2 hours and 45 minutes. - Convert 2 hours and 45 minutes to hours: \[ 2 \text{ hours} + \frac{45}{60} \text{ hours} = 2 + 0.75 = 2.75 \text{ hours} \] - Use the formula for distance: \( \text{Distance} = \text{Speed} \times \text{Time} \) \[ \text{Distance} = 4 \text{ km/h} \times 2.75 \text{ hours} = 11 \text{ km} \]
2. Calculate the Time to Cover the Same Distance Running: - The running speed is 16.5 km/h. - Use the formula for time: \( \text{Time} = \frac{\text{Distance}}{\text{Speed}} \) \[ \text{Time} = \frac{11 \text{ km}}{16.5 \text{ km/h}} = \frac{11}{16.5} \text{ hours} \] - Simplify \( \frac{11}{16.5} \): \[ \frac{11}{16.5} = \frac{11}{\frac{33}{2}} = \frac{11 \times 2}{33} = \frac{22}{33} = \frac{2}{3} \text{ hours} \] - Convert \( \frac{2}{3} \text{ hours} \) to minutes: \[ \frac{2}{3} \text{ hours} \times 60 \text{ minutes/hour} = 40 \text{ minutes} \]
The man will cover the same distance in 40 minutes when running at 16.5 km/h.