Acustomer buys a different book that has an original selling price of $38.the book is discounted 25%.the customer must pay a 6% sales tax on the discounted price o the book.

Total cost after tax 30.21.
Find the discounted price by multiplying the original price by the percent remaining to pay. 38*.75=28.5. Multiply that amount by 1.06 to represent 106% to include the addition of tax/ 28.50*1.06=30.21

The density of the cube is 40