In this question, there are numerous important information's that needed to be taken note of. It is already given that 1/12 is the commission received by the salesman on the sales price of a car. Then Sales commission of the salesman on the car = (1/12) * 21999 = 21999/12 = 1833.25 dollars So the salesman receives a commission of $1833.25 on the sales of the car that was priced at $21999. I hope you have understood the method by which the problem has been solved.