Test 1 Section 3 - #20 (page 401)

This #20 is a...drumroll please...PLUG-IN! Say k = 10. So the salesperson's commission is 10% of his sales.

He sells 2 cars, for $14,000 each, so his commission will be 10% of $28,000 in sales:

That's $2,800 in commission for our pal the salesman.

Just drop 10 in for k in all the answers, and see which ones gives you $2,800:

(A) 280(10) = 2,800

(B) 7,000(10) = 70,000

(C) 28,000(10) = 280,000

(D) 14,000/[100 + 2(10)] =116.666... 

(E) [28,000 + 10]/100 = 280.1  

Only (A) works!