I don't understand this

Asmall foreign car gete 42 miles per gallon and user 35 gallons on a trip.gasoline costs $1.05 per gallon.what was the cost of gasoline per mile driver?

Which property is illustrated by the following statement? if hxa rgi, then rgi hxa.

If a baby uses 15 diapers in 2 days, how many diapers will the baby use in a year?