How many years will the following take? a. $500 to grow to $1,039.50 if its invested at

Question:

How many years will the following take?
a. $500 to grow to $1,039.50 if it’s invested at 5 percent compounded annually
b. $35 to grow to $53.87 if it’s invested at 9 percent compounded annually
c. $100 to grow to $298.60 if it’s invested at 20 percent compounded annually
d. $53 to grow to $78.76 if it’s invested at 2 percent compounded annually