SOLUTION: Three projectors at a disco flash at regular intervals of 9, 12 and 15 seconds respectively. If they start flashing together, after how many seconds will they flash together again.

Question 960725: Three projectors at a disco flash at regular intervals of 9, 12 and 15 seconds respectively. If they start flashing together, after how many seconds will they flash together again.
Answer by dkppathak(439) (Show Source): You can put this solution on YOUR website!
Three projectors at a disco flash at regular intervals of 9, 12 and 15 seconds respectively. If they start flashing together, after how many seconds will they flash together again
LCM of 9,12,15 is qual to 180
so they will flash to gether after 180 second or 3 minutes
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