Question

Bananas are on sale for $0.40 a pound, and you have a coupon for $0.25 off your total purchase. Write a function rule for the cost of n pounds. How much would 30 pounds of bananas cost?

A) C(n)= 0.25n-0.40;$7.10 B) C(n)= 0.4n-0.40;$11.60 C) C(n)= 0.4n-0.25;$11.75 D) C(n)= 0.4n;$12.00

Answer 1

Write a function rule for the cost of n pounds and Find how much would 30 pounds of bananas cost .

To prove

First Case

First find the function rule for the cost of n pounds.

As given

Bananas are on sale for $0.40 a pound, and you have a coupon for $0.25 off your total purchase.

Here number of bananas = n pounds

Than the function becomes

C(n) = 0.4n - 0.25

Where C(n) is represented the total cost of the n pounds bananas.

Second Case

Find the cost for the 30 bananas .

Put n = 30 in the above equation.

C(30) = 0.4 × 30 - 0.25

= $11.75

Therefore the option (C) is correct.