I’m confused on how to solve this problem

Which of the following tables represents exponential functions?

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply