The traffic light at 3 diffrent road crossing change after every 48 sec. 72sec.and 100sec.respectively. if they change simultaneously at 8 am,at what time will they change again simultaneously.

 

 

Prime factorisation of 48, 72 and 100.

 

48 = 2 × 2 × 2 × 2 × 3

^{72  =  2 × 2 × 2 × 3 × 3}

100 = 2 × 2 × 5 × 5

LCM(48, 72, 100) = 3600

 

3600 seconds = 60 mins = 1 hour

 

Therefore at 8 + 1 = 9am they change again simultaneously.