Question

The sale price S (in dollars) of an item is given by the formula S=L−rL, where L is the list price (in dollars) and r is the discount rate (in decimal form). a. Solve the formula for r. r= b. The list price of the shirt is $30. What is the discount rate? The discount rate is .

Answer 1

a) S = L - rL

      = L(1 - r)

$1 - r = \frac{S}{L}$

$r = 1 - \frac{S}{L}$

$r = \frac{L-S}{L}$

b) If the list price is $30, then L = 30

So, the discount rate is $r = \frac{30 - S}{30}$