The traffic lights at three different road crossing change after every 48 seconds, 72
seconds and 108 seconds respectively. If they change simultaneously at 7 am, at
what time will they change simultaneously again?
Answers
Answer:
1) Let's take the LCM of the given times
Step-by-step explanation:
2) 48=2*2*2*3
72=2*2*2*3*3
108=2*2*3*3*3
Hence, LCM of 48, 72 and 108 = 432
So after 432 seconds they will change simutanousely..
3) We know that
60 sec = 1 min
So on dividing 432/60 we will get 7 as quotient and 12
as reminder...
Hence 432 sec = 7 min 12 sec
Therefore, The time= 7 am 7 min 12 sec
Hope this will help u all...
to find the at what time the lights will change simultaneously we need to find the LCM of 48, 72 and 108
2|48,72,108
2|24,36,54
3|12,18,27
3|4,6,9
2|2,1,3
2|1,1,3
3|1,1,1
07:00:00
= +। 0.7:12
= 07:07:12
LCM of 42, 72 and 108
=2×2×3×3×2×2×3
432÷60min = 7min 12 sec
hence, the lights will again change simultaneously at 7mins 12sec past 7 am.