A resturant manager wants to order new glasses. The ratio of the number of water glasses to the number of juice glasses in the resturant is 15 to 2.

How many juice glasses did the resturant manager order if she ordered 180 water glasses?

One way to solve this is to use a proportion.

15/2 = 180/x

Cross multiply and solve for x.

15x = 360
x = 360/15
x = 24