Please solve and explain, thanks :)

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years

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?

Big boi and travis scott are performing at the super bowl. travis scott is 62 years younger than twice big boi’s age. the sum of their ages is 70 years old. use b to represent big boi’s age. write and solve an equation.