Click on the length of the rectangle

Alength on a map is 7.5 inches. thescale is 1 inch: 5 miles. what is theactual distance? a 1.5 miles c 12.5 milesb 2.5 miles d 37.5 miles

1- 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. 2- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis. 3- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in part b?

Having a hard time understanding this question (see attachment).