Question

$5 divided by 1 hour equals what over 3 hours

Answer 1

$15 because 1 times 3 is 3 so 5 times 3 would be 15 so $15

Answer 2

5/1 = x/3
cross multiply because this is a proportion
(1)(x) = (5)(3)
x = 15

so 5/1 = 15/3...notice that proportions are nothing but equivalent fractions