If a dozen donuts is sell for $3.99, then 5 dozen is sell for 5*$3.99 = $19.95.
1 dozen means 12 donuts, then 5 dozen is equivalent to 5*12 = 60 donuts.
Given that the cost to make 3 donuts is $0.45, then we can use the next proportion to find the cost of 60 donuts:
[tex]\frac{3\text{ donuts}}{60\text{ donuts}}=\frac{0.45\text{ \$}}{x\text{ \$}}[/tex]Solving for x,
[tex]\begin{gathered} 3\cdot x=0.45\cdot60 \\ x=\frac{27}{3} \\ x=9 \end{gathered}[/tex]5 dozen donuts cost $9.00.
Profit is calculated as follows:
Profit = revenue - cost
In this case, the profit on 5-dozen donuts is:
Profit = $19.95 - $9.00
Profit = $10.95
