That's called "the least common multiple"or lcm(585,624). We write the prime factorization of each: Look at prime factor 2: 585 = 3*3*5*13 624 = 2*2*2*2*3*13 2 is a factor of 585 0 times. 2 is a factor of 624 4 times. So 2 is a factor of lcm(585,624) 4 times because 4 ≥ 0. ---------------------- Look at prime factor 3: 585 = 3*3*5*13 624 = 2*2*2*2*3*13 3 is a factor of 585 2 times. 3 is a factor of 585 1 time. So 3 is a factor of lcm(585,624) 2 times because 2 ≥ 1. ---------------------- Look at prime factor 5: 585 = 3*3*5*13 624 = 2*2*2*2*3*13 5 is a factor of 585 1 time. 5 is a factor of 585 0 times. So 5 is a factor of lcm(585,624) 1 time because 1 ≥ 0. ---------------------- Look at prime factor 13: 585 = 3*3*5*13 624 = 2*2*2*2*3*13 13 is a factor of 585 1 time. 13 is a factor of 585 1 time. So 13 is a factor of lcm(585,624) 1 time because 1 ≥ 1. ---------------------- Put it all together: 2 is a factor of lcm(585,624) 4 times. 3 is a factor of lcm(585,624) 2 times. 5 is a factor of lcm(585,624) 1 time. 13 is a factor of lcm(585,624) 1 time. So lcm(585,624) = 2*2*2*2*3*3*5*13 = 9360. Edwin