Ioana has three ropes whose lengths are 39 inches, 52 inches and 65 inches. She wants to cut the ropes into equal length pieces for magic tricks. No rope is to be wasted. What is the greatest number of inches possible in the length of each piece

13 inches

Step-by-step explanation:

To find the greatest number of inches possible in the length of each piece, we need to find the greatest common divisor of 39, 52 and 65.

So, the divisors of 39 are: 1, 3 and 13

The divisors of 52 are: 1, 2, 4, 13 and 26

The divisors of 65 are: 1, 5 and 13

Therefore, the common divisors are 1 and 13. Finally the greatest common divisor is 13. It means that the greatest number of inches possible in the length of each piece is 13 inches.