Question

The traffic lights at three different road crossing change after every 48 seconds ,. 72 seconds and 108 second respective . if they change simultaneously at 7am , at what time will they change simultaneously again ?​

Answer 1

Answer:

7 min and 12 seconds

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

48 = 2 × 2 × 2 × 2 × 372 = 2 × 2 × 2 × 3 × 3

48 = 2 × 2 × 2 × 2 × 372 = 2 × 2 × 2 × 3 × 3108 = 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.

Hope it helps you friend ;)