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# expression for word problem

A candle burns for 2 minutes and is 8 inches long the same candle is 7 and one quarter long after 3 minutes assume the candle will burn at same rate.

### 2 Answers by Expert Tutors

Justin L. | A Personalized Approach to a Standardized EducationA Personalized Approach to a Standardize...
5.0 5.0 (7 lesson ratings) (7)
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at 2 min it was 8"
at 3 min it was 7.25"

so the candle burns at .75" per minute.

Zinki J. | Physics and Mathematics TutoringPhysics and Mathematics Tutoring
4.8 4.8 (6 lesson ratings) (6)
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Hi Wesley,

I could not see any question in this. But I assume that you may want to know either the rate of burning or the total initial height of candle or how long it would take to burn the entire candle.

Assume that at time t=0 length of candle is `x`
Given at t=2 minutes, length is 8 inches
at t= 3 minutes, length is 7.25 inches

So the rate of burning of the candle or the rate at which the length of candle is decreasing = decrease in length / time duration
= (8-7.25)inches/(3-2) minutes
= 0.75 inches/minute

to find the initial length of the candle, use this formula for the times t=0 and t=2 minutes

the rate of change is same (given)

so, 0.75= (x-8)/(2-0)

solving this x= 9.5 inches

suppose it takes t` seconds to fully burn the candle
implies at t=t` length of the candle is 0 inches

so t`= .75 * 9.5 = 7.125 minutes or 7.13 minutes.