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  • The traffic lights at three different road crossing change after every 48 sec; 72 sec; and 108 sec.
Question 1:
The traffic lights at three different road crossing change after every 48 sec; 72 sec; and 108 sec., respectively. If they all change simultaneously at 8:20:00 hrs,
then they will again change simultaneously at
A. 8:27:12 Hrs
Feedback The change of interval=(LCM of 48,72,108)sec.=432.
So, for every 432 seconds i.e.7 min. 12 sec. the lights will change.
So add 7 min.12 sec.to 8:20:00 Hrs.i.e.8:27:12 Hrs.
B. 8:27:24 Hrs
C. 8:27:36 Hrs
D. 8:27:48 Hrs

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