SOLUTION: Hello! I would appreciate it if you could help me solve this word problem: Two candles of the same height are lit at the same time. The first is consumed in four hours, the seco

Algebra.Com
Question 1208637: Hello! I would appreciate it if you could help me solve this word problem:
Two candles of the same height are lit at the same time. The first is consumed in four hours, the second in three hours. Assuming that each candle burns at a constant rate, how many hours after being lit was the first candle twice the height of the second?

Found 3 solutions by Shin123, josgarithmetic, timofer:
Answer by Shin123(626)   (Show Source): You can put this solution on YOUR website!
Note that the exact height of the candles doesn't matter, since the candles burn at a rate proportional to their height (and the candles both have the same height). So we can assign a value to the height. To make computations easier, let the common height be 12.
For the first candle, every hour, the height decreases by 12/4=3. Therefore, after x hours, the height would be .
For the second candle, every hour, the height decreases by 12/3=4. Therefore, after x hours, the height would be .
Now, we need to find the time such that the first candle had twice the height of the second. This gives us the equation . Distributing the 2 on the right hand side gives Adding to both sides now gives . Subtracting 12 from both sides gives . Finally, dividing both sides by 5 gives . Therefore, the answer is hours.

Answer by josgarithmetic(39630)   (Show Source): You can put this solution on YOUR website!
CANDLE          BURN RATE      TIME         LENGTH of CANDLE

First           d/4             x             d-(d/4)x

Second          d/3             x             d-(d/3)x

Question seems to need the "length of candles" to be as .

If divide left and right by d, then ;



multiply left and right sides by 12;



and this is 2 and two-fifths hours

or two hours twenty-four minutes.

Answer by timofer(106)   (Show Source): You can put this solution on YOUR website!
You can take the original length of each candle to both be a unit of 1, for 1 candle length. Then for some expected time, since both are started at the same time, candle #1 will be and candle #2 will be .

You would have then .
Simplify this and solve for the time, x.

RELATED QUESTIONS

Hello, im stuck on this question and would like some help thanks. :) The heights, in... (answered by stanbon)
My question: Could you show me the formula to use to answer the question below? Math... (answered by ankor@dixie-net.com)
Hi, I can't solve this word problem involving right triangles: "A surveyor finds that... (answered by josmiceli)
Hi, I need help with this word problem if someone could help me i would greatly... (answered by rothauserc)
Hello, If someone could help me solve for this problem from, the Book: Intermediate... (answered by london maths tutor)
Hello, I've tried working this problem out, but my answers are coming out strange and I'm (answered by josmiceli)
Hello, I would appreciate it if you could help me out! Donna reaches into her purse... (answered by Edwin McCravy)
I don't know where to begin with this problem!! Please help. Thanks you. A candle... (answered by josmiceli)
Hello! I have a word problem that I need help solving. My problem : Two hikers are... (answered by mananth,josgarithmetic)