math
posted by m .
Write the answer to the problem as an algebraic expression. The product of two numbers is 30. One of the numbers is r. What is the other number?
Our choices are:
a) r/30
b) 30/r
c) 30r
d) 30r
I believe the answer is b but am thinking it may be c, any help?

These definitions should help you. Remember, you're looking for the product.
http://www.mathsisfun.com/basicmathdefinitions.html 
30/r