Sandy and Mark have $25.00 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 $32.50 plus 10% sales tax. To check if he has enough to purchase the book, Mark takes 35% of $32.50 and subtracts that amount from the original price. He takes 10% of the discounted selling price and adds it back to find the purchase amount.

Sandy takes 65% of the original purchase price and then computes 110% of the reduced price.

Is Mark correct?

Is Sandy correct?

Do they have enough money to purchase the book? Explain your answer using complete sentences and show your work.