386 divided by 20 is 19.3 so Greg averaged 19.3 miles per gallon.
72 is multiples of 3,9, and 12
1350$ is the right answer to your problem trust me I know this
Just subtract 20.35 from 100.8

if your bag weighs 100.8 kg and you scoop out 20.35 kg then weigh your bag it will be 80.45 bc u took out 20.35 kg of the cement to use. hope that explains it