Answer:
60
Explanation:
The smallest number that is divisible by 15, 20 , and 30, must have the needed factors of each of these numbers:
15 = 3 * 5
20 = 2 * 2 * 5
30 = 2 * 3 * 5
Then the minimum common factor must have the following factors to satisfy the divisibility of all of the numbers above:
2 * 2 * 3 * 5 = 60