SOLUTION: The height (in centimeters) of a candle is a linear function of the amount of time in hours it has been burning when graphed, the function gives a line with a slope of -0.6 suppos

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The height (in centimeters) of a candle is a linear function of the amount of time in hours it has been burning when graphed, the function gives a line with a slope of -0.6 suppos      Log On


   

Question 1090014: The height (in centimeters) of a candle is a linear function of the amount of time in hours it has been burning when graphed, the function gives a line with a slope of -0.6 suppose that the height of the candle after 11 hours is 23.4 centimeters what was the height of the candle after 7 hours
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
slope, -0.6;
Points (11, 23.4)
Equation: y-23.4=-0.6%28x-11%29
y-23.4=-0.6x%2B6.6
y=-0.6x%2B30


What was height after 7 hours?
y=-0.6%2A7%2B30
y=-4.2%2B30
highlight%2825.8%29

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
The candle burns in 0.6*4 = 2.4 centimeters  (4 is 4 hours = the time interval between "7 hours" and "11 hours").


Hence, the length of the candle was 23.4 + 2.4 = 25.5 cm.


You can solve the problem using equations.

You also can solve it using your common sense.

It is good if both answers coincide.


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For problems on burning candles see the lesson
    - Burning candles
in this site.