three fireworks are fired at the same time, then the first is fired every sixty four seconds, the second every eighty four seconds and the third every ninety six seconds. how long after the first firing will it be until they are all fired at the same time again?
+33654 You want the least common multiple (lcm) of 64, 84 and 96. One way to do this is first to find the prime factors of each number:
64 = 26
84 = 22*3*7
96 = 25*3
Now multiply together the largest powers of all the prime factors that occur:
26*3*7 = 1344 this is the lcm
So they are all fired together again after 1344 seconds
+33654 You want the least common multiple (lcm) of 64, 84 and 96. One way to do this is first to find the prime factors of each number:
64 = 26
84 = 22*3*7
96 = 25*3
Now multiply together the largest powers of all the prime factors that occur:
26*3*7 = 1344 this is the lcm
So they are all fired together again after 1344 seconds
