What is the surface area of the rectangular prism?

Math question.. plz me .. best answer all

Samuel deposited money in an account that’s pays an annual simple interest rate at 3.5%. at the end of 5 years, samuel earns $2625.00 in interest. how much money did he deposit in the account?

Mrs. robinson bought a novel at a bookstore on sale for 20% off its regular price of $29.99. mr chang bought the same novel at a different bookstore for 10% off its regular price of $25. which person received the better discount?