How many whole numbers between 200 and 500 contains the digit 4 in the standard notation

Is the following relation a function? x y 1 4 −1 −2 3 10 5 16 yes no

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?