Question

A thief runs with a uniform speed of 100 m/ minute. After one minute a policeman runs after, the thief to catch him. He goes with a speed of 100 m/minute in the first minute and increases his speed by 10 m/minute every succeeding minute. After how many minutes the policeman will catch the thief.

Answer 1

Let total time to catch the thief be n minutes 

Total distance covered by thief = (100n) metres

Total distance covered by policeman = 100 + 110 + 120 + ...+ (n - 1) terms