Question

the traffic lights at three different road crossings change after every 48 seconds , 72 seconds and 180 seconds . if they start changing simultaneously at 8 a.m., after how much time will they change again simultaneously?​

Answer 1

Answer:

8 : 07 : 12 am

Step-by-step explanation:

The traffic light at three different road crossing change after every 48seconds,72seconds and 108seconds respectively

So,

48=2×2×2×2×3

72=2×2×2×3×3

108=2×2×3×3×3

Therefore, L.CM of 48,72,108 is

(2×2×2×2×3×3×3)

=432

So, time when they change again =432seconds

But we need to find time after 8am So, first we convert 432seconds into minutes.

Time=432second= 432/600minutes

∴Time=7 minutes12 seconds

Thus,

Required time =8am+7minutes 12seconds

=8:07:12 am

HOPE THIS HELPS YOU

Answer 2

Step-by-step explanation:

first is 8:00 and 48 seconds second at8:01 and 12 seconds third 8:03