Answer:
20 basketballs in a full box
Explanation:
Let n be a full box and n-3 be a box not full, so we know that there are 8 full boxes and 5 that are not and that Noah packed 245 basketballs in total, so we can write the following equation
8n+5(n-3)=245
8n+5n-15=245
13n-15=245
13n=245+15
13n=260
n=260/13
n=20
So in a full box are 20 basketballs and 17 in the near full box