10.
5 multiplied by 2 "5 x 2" = 10
QUESTION → 
Start by subtracting 3 from both sides to get
.
Now multiply both sides by the reciprocal of 3/2, which is 2/3.
On the left, we have x, and on the right, -3(2/3) is -2.
So we have x = -2.
1/8 of 3 is 24. So he had 24 books in all.
I think its C but I'm not 100% sure