Answer:
11
Explanation:
Composite number is positive number which is greater than 1. The composite number cannot be a prime number.
The composite numbers starting from 4.
Composite numbers: 2, 4, 6, 8, 9,10, 12, 14, 15...
We need to find the two digits number that are the same and their product is not composite.
So the number 11.
11 is not a composite number.
The product of the digits: 1 times 1 = 1 which is also not a composite number.
Therefore, the answer is 11.