Brunette College offers 4 44 math classes, 2 22 science classes, 3 33 language classes, and 5 55 art classes. Sylvia needs to sign up for exactly one class in each subject. How many different combinations of classes does Sylvia have to choose from?

There are 120 combinations.

There are 4 ways she can choose the math class; 2 ways to choose the science class; 3 ways to choose the language class; and 5 ways to choose the art class:

4(2)(3)(5) = 120