A ratio compares 2+ quantities to understand how they compare to one another.For example, if you have a ratio of 3:5, it means for every 3 units of the first quantity, there are 5 units of the second. If you are told there are 15 units of the first quantity, do the following to find the number of units of the second:
Equate the ratio to the total quantities (i.e.,
3
5
=
15
?
)
Cross-multiply to solve for the unknown quantity (i.e., 15 x 5 = 3 x ?)