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A candle is 3030 centimeters tall when it is lit. It burns at a constant rate, and after 44 hours it is 2222 centimeters tall. Which function gives the height h(t)h(t), in centimeters, of the candle tt hours after it is lit?

A

h(t)=30−2th(t) = 30 - 2t

B

h(t)=30−8th(t) = 30 - 8t

C

h(t)=22−2th(t) = 22 - 2t

D

h(t)=30−4th(t) = 30 - 4t

Show answer and explanation

Answer: A

The candle loses 30−22=830 - 22 = 8 centimeters in 4 hours, which is 84=2\frac{8}{4} = 2 centimeters per hour. The starting height is 30, so h(t)=30−2th(t) = 30 - 2t.

Choice B uses the total loss of 8 centimeters as the hourly rate.

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