The number, N (in million) of VCR's sold in the United States for the years 1990 to 2001 may be approximated by the formula N = (12 + 1)/(+ + 2), where r is the time in years, with 1990 being = 0. (a) Find the number sold in 1990, 1994, and 2000.

(b) Find the rate of change of sales in 1990, 1994, and 2000.

Suppose that the average price of a VCR during the same time period was governed by the rule p = 820 - 50.

a) Find the price and total revenue from sales for 1990, 1994, and 2000.

b) Find the rate of change of total revenue for 1990, 1994, and 2000.