Alyssa spent $9.20 for 16 packs of gum. at this rate, how much would it cost alyssa to buy 30 packs of gum?

First, you divide 9.20 by 16 
which is 0.575 that is how much each pack costs
subtract 9.20 by 0.575 which is 8.625 this gives us how much does it costs for 15 packs so then we can just multiply that by 2 which is 17.25 that gives us how much does it cost for 30 packs of gum.

The answer is $17.25

5\16 x 2\5 = 10/80simplify to 1/80