question_answer

A, B and C start at the same time in the same direction to run around a circular stadium. A completes a round in 252 s, B in 308 sand C in 198 s, all starting at the same point. After what time will they meet again at the starting point?

A) 26 min 18 s

B) 42 min 36 s

C) 46 min 12 s

D) 45 min

Correct Answer: C

Solution :

[c] Required time = LCM of 252 s, 308 s and 198 s \[=(2\times 3\times 3\times 11\times 14)\,s\] \[=2772\,\,s=46\min 12\,\,s\]