Answer:
15
Explanation:
Step 1:
The least common denominator of 3, 5, and 15 is equal to the least number of equal-sized lengths each color string could have.
List the nonzero multiples of each number.
3: 3, 6, 9, 12, 15, 18, 21...
Step 2:
5: 5, 10, 15, 20, 25, 30, 35...
Step 3 out of 3:
15: 15,
30
, 45, 60...
The least common denominator is
15
So everyone please stop saying 6, 6 is incorrect.
The Answer is 15