Answer:
+20
Step-by-step explanation:
I added 20 dollars per sweatshirt. I wasn't sure if you wanted me to fill in the blanks or not, but :
5 sweat shirts is 100
8 is 160
and the 180 one is 9 sweatshirts
while the last one is 240.
The pattern makes sense in the context!!
I hope this makes sense!!
