Let's first figure out how much paint it takes to paint 1/4th of a wall. We can do this by dividing the 1/4th of a paint can by 4. This equals 1/16. Now we know that 1/4th of a wall goes to 1/16th of a paint can. We can figure out the answers now.
A: This is 8/4ths of a wall, so we can multiply the paint can by 8 to get 8/16ths of a wall, or 1/2 of a paint can for 2 walls. The answer to this must be true.
B: This is 12/4ths of a wall, so we can multiply the 1/16th by 12. This gives us 12/16 paint cans, or 3/4ths of a paint can. So yes, he can paint the wall with 1 paint can.
C: This is 20/4ths of a wall. So, again, we multiply the 1/16th by 20. This gives us 5 walls for 20/16ths of a paint can, or 5/4 of a paint can. Because 5/4ths is smaller than 1 2/3, this is true.
D: OK, this is 32/4ths of a wall, so we multiply the 1/16th 32 to get 32/16, or 2. So again, we have enough paint to paint the wall.
