99 ! do not copy from other ! 99 !

tess and dan have $24.00 each to spend at a book fair, where all students receive a 15% discount. they both want to purchase a copy of the same book, which normally sells for $24.50 plus 10% sales tax. to check if she has enough to purchase the book, tess takes 15% of $24.50 and subtracts that amount from the normal price. she takes 10% of the discounted selling price and adds it back to find the purchase amount. dan takes 85% of the normal purchase price and then computes 110% of the reduced price. is tess correct? is dan correct? do they have enough money to purchase the book? explain your answer using complete sentences, and show your work.

Tess:15% of 24.50 = 0.15(24.5) = 3.675 -- this is your 15% discount
you need to subtract the normal price 24.50 - 3.675 = 20.825 this is the reduced price... 10% of discounted selling price = .10(20.825) = 2.0825
You add back to find the purchase price = 20.825 + 2.0825 = 22.9075 rounds to 22.91 Tess is correct

 Dan:  85% of the normal purchase price = 0.85(24.5) = 20.825
 110% of reduced price = 1.10 (20.825) = 22.9075 rounds to 22.91 Dan is correct

Also they both have enough money

  What I'm trying to say is subtracting 15% is the same as paying 85 you know what I mean and finding 10% of the selling price and adding that back to the discount price to find purchase price is the same as adding 110% of reduced price to get purchase price. You know what I'm saying 

$24.50 x 0.85 = $20.825 x 1.10 = $22.9075 < $24.00, therefore Tess and Dan have enough money. 

So confused right here i need it to be more clearer