The answer is fully given in the picture below. Hope it helps!
We cant Answer it because the amount of cards presented is incorrect
If 101 use 3/5 for his Artwork, then the space remaining for 102 is:
5/5 - 3/5 = 2/5 (since the whole wall represents 100% or 5/5 or 1)
I get:
24 = 3x-12
add 12 to both sides
36 = 3x
divide each side by 3 and you will get 12