Incorrect
Explanation
Only once because as soon as you subtract 10 from 100 it now becomes 90, therefore you wouldn’t be subtracting 10 from 100 anymore.
Solve this puzzle
1 is 3, 3 is 5, 5 is 4, 4 is perfect. Why?
5 = 4 4 has 4 letters 3 = 4 4 is a prime number