Candy is on sale for $0.75 each. you have a coupon for $0.25 off your total purchase. write a function rule for the cost of n pieces of candy.

a. c(n)0.25n-0.75
b. c(n)=0.75n-0.25
c. c(n)=1.0n
d. c(n)=0.75n

The answer is B. C(n) = 0.75n - 0.25.
Let n be the number of pieces. The price for 1 piece is $0.75. The price C for n pieces without a coupon is n * $0.75: C(n) = 0.75n. The coupon value is $0.25. So, this value must be subtracted from the total price of n pieces. Since the coupon values in independent on the number of pieces, the price C for n pieces with the coupon will be: C(n) = 0.75n - 0.25. Therefore, the correct choice is B.

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.