one gear of pulley rotates at a speed of 3 rev/sec another gear roates at 5 rev/sec. if both start together after how many seconds will they be together again	Choose the most appropriate option
A) 3 sec	B) 5 sec	C) 15 sec	D) 20 sec	E) 25 sec

Rationale: 3 rotates 3 , 6,9 , 12,15 5 rotates 5 , 10,15 ans is 15 answer : c
Answer: C