Question

the traffic light at three diffrent road crossing change after every 48 seconds 78second and 108seconds if they change simultaneously at7a.m at will they change sinultanesously again​

Answer 1

Given that traffic light at three different road crossing change after every 48 seconds,72 seconds and 108 seconds respectively. 48 = 2 × 2 × 2 × 2 × 3 72 = 2 × 2 × 2 × 3 × 3 108 = 2 × 2 × 3 × 3 × 3 Hence LCM of 48, 72 and 108 is (2 × 2 × 2 × 2 × 3 × 3 × 3) = 432 That is after 432 seconds they will change simultaneously 432 seconds = 7 min 12 seconds Thus the traffic lights change simultaneously at 7:7:12 am