Chapter 6, Problem 1STP

To determine

To Find:

The function that can be used to find the final price of a tent that originally cost d dollar , if the $5.00 coupon is applied after the store discount.

Answer to Problem 1STP

B

Explanation of Solution

Given Information:

A sporting goods store is discounting all camping equipment by 20% during the off-season.Charles also has a coupon good for $5.00 off his next purchase from the store . Calculation:

  $\begin{array}{l}Given\\ \text{d = the original cost of the tent in dollar}\\ \text{Discount given =20\%}\\ \text{Charles discount coupon = \$5}\text{.00(applied after the 20\% discount)}\\ \text{So, }\\ \text{First the store will give a discount of 20\% on the original }\\ \text{price of tent:}\\ \text{Price of tent after discount = }d-20\%(d)\\ =100\%(d)-20\%(d)\mathrm{.......}[100\%=1]\\ =(100\%-20\%)d\\ =80\%(d)\\ =\frac{80}{100}(d)\\ =0.80d\\ \text{Now , on this price , Charles will get extra discount of \$5}\text{.00 }\\ \text{due to his coupon :}\\ \text{Final price of tent = 0}\text{.80}d-5\\ \text{⇒}P(d)=(0.8\times d)-5\\ \text{Hence, }\\ the\text{ correct option is B}\text{.}\end{array}$