Math, asked by kaashvi808, 1 year ago

The traffic light at different roads crossing change after every 72 seconds 90 seconds and 80 seconds respectively after how much time will they change simultaneously again?

Answers

Answered by bhandariaditya309
1

Answer:72seconds 90seconds 80seconds and will go on

Step-by-step explanation:

Answered by BrainlyPARCHO
0

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If the traffic lights change simultaneously at 8 a.m, then they will change simultaneously again after the LCM of the duration i.e. 48 s, 72 s and 108 s.

LCM of these durations by prime factorisation

48 = 2 × 2 × 2 × 2 × 3 = 2⁴ × 3

72 = 2 × 2 × 2 × 3 × 3 = 2³ × 3²

108 = 2 × 2 × 3 × 3 × 3 = 2² × 3³

LCM of 48, 72 and 108 is 2⁴ × 3³ = 432 seconds.

Hence, They will change after 432 seconds i.e. 7 minutes 12 seconds.

The traffic lights will change after:

8 am + 7 minutes 12 seconds

  • 08 : 07 : 12 am
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