At a local animal shelter there are 12 small - size dogs and 5 medium - size dogs. every day, the small size dogs are given 12.5 ounces of dry food and the medium -size dogs are each given 18 ounces of the same dry food. how many pounds of dry does the shelter serve in one day?

Small Dogs: 12 dogs, each given 12.5 ounces of food a day.
                     So 12 * 12.5 = 150 ounces
Medium Dogs: 5 dogs, each are given 18 ounces of food a day.
                     So 5 * 18 = 90 ounces.
150 = 90 = 240 ounces.
                     Now to convert to pounds.
16 ounces in 1 pound. 
240/16 = 15.
15 pounds a day of dog food is served.

In this problem it decreased 20%