Question

A salesperson is paid a flat rate plus a fixed percentage of her sales. Last month, she sold $16,000 worth of goods and was paid $1,600. Two months ago, she had $12,000 in sales and was paid $1,400. This month she sold $11,000 worth of goods. How much will she be paid?
$550
$855
$1,100
$1,350

Answer 1

Let base pay = b and commission rate = r.

b + 16000r = 1600
b + 12000r = 1400

Subtract: 4000r = 200 → r = 0.05 (5%).
Then b + 12000(0.05) = 1400 → b + 600 = 1400 → b = 800.

For $11,000 sales: pay = 800 + 0.05·11000 = 800 + 550 = $1,350.