Question

Naveen walking at a speed of 15 km/h reaches his office 20 minutes late. Next time he increases his speed by 5 km/h, but he finds he is still late by 5 minutes. What is the distance of his office from his house?

A 18 km Correct Answer Incorrect Answer
B 12 km Correct Answer Incorrect Answer
C 15 km Correct Answer Incorrect Answer
D 20 km Correct Answer Incorrect Answer
E None of these Correct Answer Incorrect Answer

Solution

Let the distance be D. D/15 = T + 20/60 ……. (i) D/20 = T + 5/60 ……. (i) Form (i) and (ii) we get, D x 1/60 = 15/60 D = 15 km. Alternate method: Distance = Time gap× product of speeds/ gap of speed = 15 min×15×20/(20-15) = 15/60 hrs ×15×20/5 = 15 Km


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