Question

Plz help! 25 points!

10. Soda is on sale for $0.75 a can, and you have a coupon for $0.50 off your total purchase. Write a function rule for the cost of n sodas. How much would 10 sodas cost?

A. C(n) = 0.5n - 0.75; $4.25
B. C(n) = 0.75n - 0.5; $7.00
C. C(n) = 0.5n - 0.5; $4.50
D. C(n) = 0.75n; $7.50

12. The function b(n) = 6n represents the number of light bulbs b(n) that are needed for n chandeliers. How many lightbulbs are needed for 15 chandeliers?

A. 90 lightbulbs
B. 2 lightbulbs
C. 96 lightbulbs
D. 80 lightbulbs

Answer 1

10.: B. C(n) = 0.75n - 0.5; $7.00

12.: A. 90 light bulbs

Explanation:

10. One soda costs 0.75. n sodas cost 0.75n. Then you subtract the coupon amount, so you pay 0.75n - 0.5.

The cost function is:

C(n) = 0.75n - 0.5

The cost of 10 sodas is:

For 10 sodas, n = 10.

C(10) = 0.75 * 10 - 0.5

C(10) = 7.5 - 0.5

C(10) = 7

Answer: B. C(n) = 0.75n - 0.5; $7.00

12. b(n) = 6n

The number of chandeliers is n.

If n = 15, then you have:

b(15) = 6 * 15

b(15) = 90

Answer: A. 90 light bulbs

Answer 2

10. B. C(n) = 0.75n - 0.5; $7.00

12 A. 90 lightbulbs

Explanation:

10. Cost of the purchase = number of cans * cost per can - coupon

We know the cost per can is .75 and the coupon is a one time coupon for .50

C(n) = n * .75 - .5

If we let n=10 to buy 10 cans

C(10) = 10*.75 -.50

= 7.50 - .5

= 7.00 is the cost of 10 cans

12. b(n) = 6n where n is the number of chandeliers

b(n) is the number of light bulbs

If we have 15 chandeliers how many light bulbs do we need?

b(15) = 6*15 = 90

We will need 90 light bulbs