The total he earns is the sum of two parts. One part is the $200 per car. The other part is the 3% commission.
total earnings = $200 per car + 3% commission on amount of sales
Let's look at the $200 per car first.
He sold 3 cars.
He earns $200 for each car he sells, so just from that he earns
3 * $200 = $600.
Now we look at the 3% commission.
He earns 3% of the total amount of sales.
The total amount of sales for the 3 cars was $32,343.
He earns 3% of that amount, so his 3% commission is
3% of $32,3243 = 3% * $32,343 = 0.03 * $32,343 = $970.29
The total earnings are the sum of the two parts.
$600 + $970.29 = $1570.29
