Question

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. What is the cost of the most expensive book I can buy with my money and the coupon? (Assume that there are books of every possible price in the bookstore. It's a large bookstore!)

Answer 1

Answer:

The cost of the most expensive book which he can buy with his money is less than or equal to 43.5

Step-by-step explanation:

Given : I'm at a bookstore with $35 in my pocket and a 20%-off coupon.

To Find: . What is the cost of the most expensive book I can buy with my money and the coupon?

Solution :

let the cost of most expensive book be x

Since there is 20 % of on every book

So, After 20 % off on the most expensive

The cost will be :  x  - (x of 20%)

                             $=x-\frac{20}{100} x$

                             $=\frac{80}{100} x$

                             $=\frac{4}{5} x$

Since we are given that he has only $35 so he cannot pay more than 35

so, equation becomes :

$\frac{4}{5} x\leq 35$

$x\leq\frac{5*35}{4}$

$x\leq\frac{175}{4}$

$x\leq43.5$

So , the cost of the most expensive book which he can buy with his money is less than or equal to 43.5

Answer 2

Answer:

$43.75

Step-by-step explanation:

Let x represent the cost of the book.  We have a 20% off coupon; this means we will pay 100-20 = 80% of the cost.

80% = 80/100 = 0.8; this means we the cost we pay will be represented using the expression 0.8x.

Since we only have $35, this gives us the equation

0.8x = 35

Divide both sides by 0.8:

0.8x/0.8 = 35/0.8

x = $43.75