George’s car can drive 30 miles on 1/2 gallon of gas. how many gallons of gas will he use to drive 20 miles?

The best way to do this is to set up a proportion

30       20
  =
0.5      x

then cross multiply and divide

20 × 0.5 = 10/30=1/3

he needs 1/3 tank of gas to drive 20 miles

I hope I've helped!

Ithink it’s a or c