Question 123116
Why not reduce {{{5/66}}}?
Because it can not be reduced. Why, because the numerator and the denominator have no common factor (besides 1).
The factors of 5 ( a prime number) are 1 and 5.
The factors of 66 ( a composite number) are 1, 2, 3, 6, 11, 22, 33, and 66
So you see, there is no common factor that can be cancelled!