Suppose you deposit $$600$ each year for $20$ years in a savings account paying $5\%$ compounded annually.

a$)$ How much would the account contain after $20$ years? How much of the FV did you actually contribute?

$P=600$

$FV=(1+0\mathrm{.}05{)}^{20}600$

$=2\mathrm{.}65329600$

$=1\mathrm{.}591\mathrm{.}98$

$i=0\mathrm{.}05$

$=2\mathrm{.}65329600$

$t=20$

$=1,591\mathrm{.}98$

$=20$

If you could double only one of these, $$600$ amount invested$-5\%$ interest rate$-20$ years of time, which would benefit you more?

b$)$ The amount invested. How much of the FV did you actually contribute?