20% of a number is 60 . What is the number ?

How do you do this geometry problem

One of the same side angles of two parallel lines is 20° smaller than the other one. find the measures of these two angles.

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.