$($a$)$In cell A$6,$ type $1.$ Rather than copying the numbers $2$ to $25,$ we can fill down based on the formula in cell A$7$ which is $=$ A$6+1.$ Locate A$7($Since this is where the formula begins$)$ by clicking on the center of the cell. Go to the far lower right hand corner of cell A$7$ and hold down the left mouse button when you see the cursor change. Holding the left mouse button down, drag the cell down to year $40$ and let go off the mouse button. Couple A opens a bank account and decides to deposit $$1800\mathrm{.}00$ at the end of each year for $8$ years in an account which earns $8\%$ interest compounded annually for $40$ years. Year $8$ is the last time they deposit any money meaning there is no deposit value for years $9$ to $40.$ Remember that the Interest column is for the Interest formula, do not just put in the interest rate. When the couple opens the bank account $($the first year$),$ there is no money in Beginning Balance. Set up your spreadsheet for Couple A accordingly. You should get $$22331\mathrm{.}81$ for your ending balance for year $10.$

What is the ending balance for Cuple A after $40$ years? $

How much did Couple A actually deposit? $

What is the total amount of interest earned by Couple A$?$ $

$($b$)$Couple B decides to "live it up$"$ for the first $8$ years, meaning there is no deposit value for years $1$ to $8.$ At the end of year $9,$ they deposit $$1800\mathrm{.}00$ at the end of each year in an account which earns $8\%$ interest compounded annually. Set up your spreadsheet for Couple B$,$ showing their financial status for $40$ years. You should get $$3744\mathrm{.}00$ for your ending balance for year $10.$

What is the ending balance for Couple B after $40$ years? $

How much did Couple B actually deposit? $

What is the total amount of interest earned by Couple B$?$ $

$($c$)$At what year has Couple B$\text{'}$s account exceeded Couple A$\text{'}$s account $?$

$($d$)$At the year couple B$\text{'}$s account exceeded couple A$\text{'}$s account $($your answer from part c$),$ in total how much more had couple B deposited than couple A$.$