Can someone help me asap? Ik it’s easy but not good at maths lol

Which of the following best describes the graph below? a. it is a function, but it is not one-to-one. b. it is a one-to-one function. c. it is not a function. d. it is a many-to-one function.

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?

How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid in order to get a 40% solution of acid?