Answer:
Ms. Dunn bought 7 slices of pie.
Step-by-step explanation:
With the information provided, you can write the following equations:
x+y=24 (1)
0.80x+0.30y=10.70 (2), where:
x is the number of slices of pie
y is the number of cookies
First, you can solve for x in (1):
x=24-y (3)
Next, you have to replace (3) in (2) and solve for y:
0.80(24-y)+0.30y=10.70
19.2-0.80y+0.30y=10.70
19.2-10.70=080y-0.30y
8.5=0.5y
y=8.5/0.5
y=17
Finally, you can replace the value of y in (3) to be able to find the value of x:
x=24-17
x=7
According to this, the answer is that Ms. Dunn bought 7 slices of pie.
