Help please qwq im idek but plz helppp

If the average of x,y and z is 15 what is their sum

Gia opened two savings accounts at two different banks. one account earns an annual 3.4% simple interest, and the other earns half as much. if she deposited $500 in each account, how much total interest will she have earned in 5 years? a. $34.00 b. $25.50 c. $51.00 d. $510.00

In the triangle below, what is the length of the side opposite the 60° angle?