InterviewSolution
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InterviewSolution
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The traffic lights at three different road crossings change after every 48 seconds, 72 seconds and 108 seconds respectively. If they change simultaneously at 7 a.m. at what time will they change simultaneously again? |
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Answer» L.C.M. of 48, 72, 108 = 2 x 2 x 2 x 2 x 3 x 3 x 3 = 432 sec. After 432 seconds, the lights change simultaneously. 432 second = 7 minutes 12 seconds Therefore the time = 7 a.m. + 7 minutes 12 seconds = 7 : 07 : 12 a.m. L.C.M of 48,72,108 can be taken to find the intervals of change =432 secAfter 432 sec = 432÷(60×60) =432÷3600 =0.12 hrs Hence, next simultaneous change will take place at = 8.00 am +0.12 =8.12 am |
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