Question

Bill and Mary Ann went to the Viola bakery. Bill bought 5 pies and 7 donuts for ​$12.65. Mary Ann bought 6 of each for ​$12.30. What is the price of each type of​ pastry?

Answer 1

Pies=$0.85

Donuts= $1.20

Explanation:

In the equation let p stand for the number of pies and d stand for the number of donuts.

To solve this set up 2 equations, one representing bill and the other representing Mary Ann.

• Bill's equation is 5p+7d=$12.65.
• Mary Ann's equation is 6p+6d=$12.30

Then solve using a system of equations. Systems of equations can be solved using elimination or substitution. I will use substitution. Solve bill's equation for p. This gives you
`p=(12.65-7d)/(5)`. Then, you can substitute that into Mary Ann's equation. This looks like
`6\cdot (12.65-7d)/(5)+6d=12.3`. Solve for d. Once you solve d=1.20. Finally, substitute 1.20 back into either Bill's or Mary Ann's for d and solve for p. No matter which equation you use p=0.85.