A person reaches his destination 40 minutes late if his speed is 3 km/hr, and reaches 30 minutes before time if his speed is 4 km/hr. What is the distance of his destination from the starting point (in km)?

A12

B13

C10

D14 ✓ Correct

Correct answer: (D) 14

Explanation

The distance is 14 km.

Time difference between the two speeds = 40 + 30 = 70 min = 7/6 hr.

d/3 - d/4 = 7/6.

d/12 = 7/6.

d = 12 * 7 / 6 = 14 km.

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