Profit is calculated by subtracting the cost of the product from the income the profit brought in:
P = s - cP=s−c Where:
PP is the profit of the enterprise. $48 for this problem.
ss is the sales of the products. What we need to solve for.
cc is the cost of the products. $60 for this problem.
Substituting and solving for ss gives:
48 = s - 6048=s−60
48 + color(red)(60) = s - 60 + color(red)(60)48+60=s−60+60
108 = s - 0108=s−0
108 = s108=s
s = 108s=108
However, we need to know how much Camille is selling each doughnut for. The formula for this is:
s = d * ns=d⋅n
Where:
ss is the sales, from the solution above we know the sales where $108$108.
dd is the price of a doughnut, what we need to solve for.
nn is the number of doughnuts sold. The problem tells us Camille sold 8080 doughnuts.
Substituting and solving for dd gives:
108 = d * 80108=d⋅80
(108)/color(red)(80) = (d * 80)/color(red)(80)10880=d⋅8080
1.35 = (d * color(red)(cancel(color(black)(80))))/cancel(color(red)(80))
1.35 = d
d = 1.5
In the original equation we can substitute dn for s to give:
P = dn - c
If we want a generic formula for Profit based on the number of donuts sold we can substitute:
$1.35 for d as this is the sales price per doughnut
$60 for c as the cost Camille paid for the doughnuts
Giving:
P = 1.35n - 60