Answer:
About 1 gal
Step-by-step explanation:
When you are estimating with fractions, you should round them off to the closest integers that you can work with in your head.
⅓, ⅕, and ½ are all close to zero, but that's absurd, because Neil clearly has some paint .
Instead, let's estimate that ⅓ gal + ⅕ gal make about ½ gal.
They still have the other ½ gal, and
½ gal + ½ gal = 1 gal.
Neil has about 1 gal of paint.
