the traffic lights at three different road crossings change after every 48 seconds, 72 seconds and 108 seconds. if they start changing simultaneously at 8 am after how much time will they change again simultaneously?
Answers
Answered by
9
Hey!!!!
Basically we will take the LCM of the time intervals.
Thus By Prime Factorisation Method,
48 = 2⁴ x 3
72 = (2 x 3)² x 2
=> 72 = 2³ x 3²
108 = 3³ x 2²
Thus LCM(48,72,108) = 2⁴ x 3³
=> LCM = 16 x 27
=> LCM = 432 seconds
=> 7 min 2 seconds
Thus 8am + 7 min 2 seconds
Answer = 8 : 07 : 02 AM
Hope this helps
Basically we will take the LCM of the time intervals.
Thus By Prime Factorisation Method,
48 = 2⁴ x 3
72 = (2 x 3)² x 2
=> 72 = 2³ x 3²
108 = 3³ x 2²
Thus LCM(48,72,108) = 2⁴ x 3³
=> LCM = 16 x 27
=> LCM = 432 seconds
=> 7 min 2 seconds
Thus 8am + 7 min 2 seconds
Answer = 8 : 07 : 02 AM
Hope this helps
nehasinghx1p6celu:
thanks but can u plz make it a lil simple as I am looking for the solution for a 6 grade student
sure
instead of finding LCM by this method you can find LCM by the trial and error method. I know that's really annoying method
☹️
nothing more can be done :(
Answered by
8
Hey mate !!
Here's the answer !!
Refer to the attachment !!
Hope it helps !!
Cheers !!
Here's the answer !!
Refer to the attachment !!
Hope it helps !!
Cheers !!
Attachments:
thanks but I have to explain this to my 6 grade child and this is not so easy. can u make it simple
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