Answer:
Step-by-step explanation:
The cost function c(n) for n T-shirts can be written according to the problem statement:
[tex]c(n)=\begin{cases}20+12n&\text{for }n<10\\20+10n&\text{for }10\le n\le20\\20+7n&\text{for }n>20\end{cases}[/tex]
For an order of 15 shirts, the cost will be ...
c(15) = 20 +10(15) = 170
The soccer team's 15 shirts will cost $170.