We have the sum of cubes identity

and observing that 1 + 4 = 2 + 3, we have

and

Then

Alternatively, we have the well-known sum of cubes formula

The sum under the square root is this sum with
. Then

and so the square root again reduces to 15.
Answer:
I suppose it has 4 digits.
Step-by-step explanation:
The fractional equivalent of the repeating decimal would be 15/99.
Can u send the question to be more clear