Help please! A bookstore bought a case of 10 books at a wholesale price of $84. The bookstore will sell the books at a 25 percent markup, and each book will be sold for the same amount. How much will they sell each book in the case for?

A. $8.40

B. $10.50

C. $105.00

D. $105.80

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.

7. if the value of x varies directly with the value of y, and x = 3 when y = 21. what is the valu y, and x = 3 when y = 21. what is the value of x when y = 105?

What is the area of the triangle 10 13 12