Answer:
C. He would solve 32 math problems if he played video games for 8 hours.
Explanation:
Create the following proportion to find the number of math problems for 8 hours:
4/16 = 8/x
Cross multiply.
4 x x = 4x
16 x 8 = 128
4x = 128
x = 32
If Tom plays video games for 8 hours, he'll solve 32 math problems.
Create the following proportion to find the number of math problems in 9 hours:
4/16 = 9/x
Cross multiply.
4 x x = 4x
16 x 9 = 144
4x = 144
x = 36
If Tom plays video games for 9 hours, he'll solve 36 math problems.