How to solve which one is closest to 27.8 × 9.6

If the cost to mail a package is an initial $5 and $0.28 for every pound the total cost to mail a package was $11.27, how much did the package weigh?

Miranda drove her car 112 miles on a 4 gallons of gas and 182 miles on 6.5 gallons. how many gallons would she need to drive 420 miles?

A11 gram sample of a substance that’s used to treat thyroid disorders has a k-value of 0.1247