Pets stores

Pets Plus and Pet Planet are having a sale on the same aquarium. At Pets Plus the aquarium is on sale for 30% off the original price and at Pet Planet it is discounted by 25%. If the sales tax rate is 8%, which store has the lower sale price? How much will you save by buying the aquarium there? Round to the nearest cent.

Store	original price
Pets Plus	118
Pet Planet	110

Correct answer:

a =  89.208 USD
b =  89.1 USD
x =  0.1 USD

Step-by-step explanation:

$$\begin{gathered} r_1=100\%-30\%=1-\frac{30}{100}=0.7 \\ {r}_2=100\%-25\%=1-\frac{25}{100}=0.75 \\ s=100\%+8\%=1+\frac{8}{100}=1.08 \\ a=118\cdot r_1\cdot s=118\cdot 0.7\cdot 1.08=89.208\text{USD} \end{gathered}$$

$$\begin{gathered} b=110\cdot r_2\cdot s=110\cdot 0.75\cdot 1.08=\frac{891}{10}=89.1=89.1\text{USD} \\ b<a \end{gathered}$$

$x=a-b=89.208-89.1=0.1\text{USD}$

Try another example