Question

Mary has $20 .she wants to buy a book that is marked do 30% from it's original price of $28. It the sales tax is 2.5%,does Mary have enough money to buy the book

Answer 1

she does not have enough!

Step-by-step explanation:

thirty percent of $28 is $8.4, so you would subtract the two leaving you with $19.6

2.5 sales tax of $19.6 is $0.49

Adding those two the total comes to $20.09 which is just over the budget!

Answer 2

Answer: She does not have enough money.

She needs 9 cents (aka $0.09)

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Step-by-step explanation:

A discount of 30% means Mary would pay the remaining 70% (because 100-30 = 70)

The decimal form of 70% is 0.70

Let A = 0.70 since we'll use it later.

An increase of 2.5% means we will also have the multiplier 1.025; which you can think of it like saying 100% + 2.5% = 1 + 0.025 = 1.025

Let B = 1.025 since we'll use it later

Multiply the values of A and B to get: 0.70*1.025 = 0.7175

This is the net multiplier when combining the 30% discount and 2.5% tax.

The original price $28 then becomes 0.7175*28 = 20.09 which is 9 cents (aka $0.09) over the goal of $20

Therefore, Mary does not have enough money to buy the book. She'll need that remaining 9 cents.