We just need to work both numerator and denominator.
Both numbers are even numbers, so both of them can be divided by 2:
[tex]\frac{20}{32}=\frac{20/2}{32/2}=\frac{10}{16}[/tex]So far the fraction has been simplified from 20/32 to 10/16. However, it can be simplified further, since again, 10 and 16 are both even numbers:
[tex]\frac{20}{32}=\frac{10/2}{16/2}=\frac{5}{8}[/tex]Now we have simplified the fraction 20/32 to 5/8. This can not be simplified further since 5 and 8 do not have a common divisor other than 1.
Then, the answer is 5/8.