three lightships flash simultaneously at 6 00 a.m.
the first lightship flashes every 12 seconds, the second lightship flashes every 30 seconds and the third lightship flashes 66 seconds.
at what time will the three lightships next flash together?

Question

three lightships flash simultaneously at 6 00 a.m.
the first lightship flashes every 12 seconds, the second lightship flashes every 30 seconds and the third lightship flashes 66 seconds.
at what time will the three lightships next flash together?

mathmagician · Answer

you should find least common multiple of 12, 30 and 66

anonymous · Answer

2x2x3x5x11 then what?

mathmagician · Answer

At first you have to Express the numbers as product of prime factors.
Then Take the prime numbers with highest power for all prime numbers.
And finally calculate product of the numbers taken.

anonymous · Answer

I still dont understand: Take the prime numbers with highest power for all prime numbers. And finally calculate product of the numbers taken.

mathmagician · Answer

LCM is 2x2x3x5x11=660 now convert this number to minutes and add to 6.00 pm

anonymous · Answer

to convert the number to minutes, i must have to divide it by 60?

mathmagician · Answer

right

anonymous · Answer

the answer is 6 11 a.m.?

anonymous · Answer

Yes!