Question

The traffic lights at three different roads crossing change after every 48 seconds, 72 seconds, 108 seconds respectively if the change simultaneously at 7 am at what will they change simultaneously again.

Answer 1

Answer:

Step-by-step explanation:

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

Taking LCM for,

48, 72 and 108 i.e (2 × 2 × 2 × 2 × 3 × 3 × 3)= 432

We have,

432 seconds = 7 min 12 seconds

Hence,after 7 min and 12 seconds they will blink simultaneously.

Answer 2

Answer:

LCM of 48,72,108 is 2592

that is 43min 12sec

so at 7:43:12 am, traffic lights change simultaneously