Please help fast and thank u

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

You earn a 12% commission for every car you sell. how much is your commission if you sell a $23,000 car?

At the beginning of year 1, carlos invests $600 at an annual compound interest rate of 4%. he makes no deposits to or withdrawals from the account. which explicit formula can be used to find the account's balance at the beginning of year 5? what is, the balance?