Answer: the number of single-crust cherry pies that was sold is 16
the number of double-crust apple pies that was sold is 20
Step-by-step explanation:
Let x represent the number of single-crust cherry pies that was sold.
Let y represent the number of double-crust apple pies that was sold.
The total number of pies sold on a busy Friday was 36. This means that
x + y = 36
Grandma's Bakery sells single-crust apple pie for $6.99 and double-crust cherry pie for $10.99. If the amount collected for all the pies that day was $331.64, it means that
6.99x + 10.99y = 331.64 - - - - - - - - -1
Substituting x = 36 - y into equation 1, it becomes
6.99(36 - y) + 10.99y = 331.64
251.64 - 6.99y + 10.99y = 331.64
- 6.99y + 10.99y = 331.64 - 251.64
4y = 80
y = 80/4 = 20
x = 36 - y = x = 36 - 20
x = 16
