Answer: your answers are correct. I inserted an image of the answers.
This is a volume question. 8x8x8, 512 cubic inches of water.
Total would be $67.2! Each shirt would cost $16.8 with tax!
Let p = pictures only
let f = pictures with frames
p + f = 100
5p + 10f = 875
Solve for one variable in the first equation then plug into the second
p = 100 - f
5(100 - f) + 10f = 875
500 - 5f + 10f = 875
500 + 5f = 875
5f = 375
f = 75
75 pictures with frames were sold