B$78$: Income tax expense: Since we know the income that is subject to taxes $($B$77)$ as well as the

income tax rate $($B$38),$ we can calculate the income tax expense as $B77B38$ However the rule in

our situation is that we don't get a tax refund $($l$.$e$.,$ there can be no negative tax values$)$ in years that

we don't make a profit, meaning there are no taxes when our income is negative. So$,$ we need to use

the IF$-$function to ensure that our income tax expense is calculated only when our profits are greater

than $0.$ Otherwise our tax expense should be set to $0$

As you have learned earlier in earlier assignments, the IF$-$function

$($logical$\_$test, value$\_$if$\_$true,$\_$value$\_\_$f$\_$false$)]$ consists of three parts

a$.$ First, we enter a logical test, which is a statement that needs to result in either TRUE or

FALSE. Our logical test is the question of whether income before taxes is greater than zero:

$B77>0.$

b$.$ Second, we enter the value of the cell $(B78)$ in case the logical test results in TRUE. That

value is the tax expense calculated as income before taxes times the tax rate: B$77.$B$38$

c$.$ Third, we enter the value of the cell $($B$78)$ in case the logical test results in FALSE That value

is $0$ in our worksheet. So$,$ the entire formula for the income tax expense reads:

$=IF(B77>0,B{77}^{*}B38,0)$

B$79$; Income after taxes: Lastly, we deduct the income tax expense from the income before taxes,

which gives us the income after taxes. This is our result value that we are most interested in $($and that

we want to maximize by using Solver$)$: