Practice!

Sample Problem

The ratio of the number of adults to the number of children in a library is 12:5. If there are 45 children members in the library, how many adults are there at the library?

adults

Solution

Here, we can use the method of finding an equivalent ratio to find the number of adults.

12:5 = ___ :45

45 ÷ 5 = 9, so each part of 12:5 is multiplied by a common factor of 9. Then,

12:5 = (12 × 9) : (5 × 9) = 108:45

Thus, there are 108 adults at the library.