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Alex and Lara have $21.00. each to spend at a book fair, where all students receive a 35% discount. They both want to purchase a copy of the same book, which normally sells for $28.50 plus 10% sales tax. To check if he has enough to purchase the book, Alex takes 35% of $28.50 and subtract that amount from the normal price. He takes 10% of the discounted selling price and adds it back to find the purchase amount. Lara takes 65% of the normal purchase price and then computes 110% of the reduced price. Is Alex correct? Is Lara correct? Do they have enough money to purchase the book? explain your answer using complete sentences and show your work.​

2 Answers

4 votes
This a a lot ok ima help u
User Atralb
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To begin, let's find how much the book is including tax and the student discount. Once we find this, we can see if Lara or Alex is correct and if they can afford it.

First, we want to compute the student discount. The student discount is 35%. Thus, we can do 0.65 x 28.50 = 18.525. With 10% tax, we have 18.525 x 1.1 = 20.3775. Which will round up to $20.38.

Now, lets see what Alex did and if he got the same answer. First he takes 35% of $28.50 and subtracts it from the normal price.

.35 x 28.50 = 9.975

28.50 - 9.975 = 18.525

Then he takes 10% of this number and adds it back.

.10 x 18.525 = 1.8525

18.525 + 1.8525 = 20.3775

Alex has the correct answer.

Next, we will see if Lara computed it correctly.

First she takes 65% of the normal price.

0.65 x 28.50 = 18.525

Then she computes 110% of the reduced price.

18.525 x 1.10 = 20.3775

Lara also gets the correct answer.

So, do they have enough money to purchase the book?

YES:

$20.38 < $21

Is Alex correct?

YES

Is Lara correct?

YES

Although they used different methods to get the answer, they both got the right one!

User LostMyGlasses
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