• # question_answer One pendulum ticks 57 times in 58 sec, while another ticks 608 times in 609 sec. If they started together, then how often will they tick together in the first hour? A) 47                    B)          53 C) 57                    D)          67

LCM of 58/57 and 609/608 sec. In 1 hour, they will tick together = 3600 x 19/1218=56.1 times after the first stroke $\Rightarrow$ 57 times per hour.