SOLUTION: My question: Could you show me the formula to use to answer the question below? Math Question: I have 2 candles with equal lengths. Both candles are lit at the same time. Ca

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Question 72978: My question: Could you show me the formula to use to answer the question below?
Math Question: I have 2 candles with equal lengths. Both candles are lit at the same time. Candle A burns out at 9 hours. Candle B burns out at 6 hours. At what time is the slower burning candle twice as long as the faster burning candle?
Any help you can provide would greatly be appreciated. Thank you.
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
2 candles with equal lengths. Both candles are lit at the same time. Candle A burns out at 9 hours. Candle B burns out at 6 hours. At what time is the slower burning candle twice as long as the faster burning candle?
:
For convenience let's assign a length of 9" to the candles
That means:
Candle A burns 1"/hr and candle B burns 1.5"/hr
:
Let t = hrs until A is twice as long as B
An equation:
9 - 1t = 2(9 - 1.5t)
9 - t = 18 - 3t
-t + 3t = 18 - 9
2t = 9
t = 4.5 hrs
:
Check:
candle A after 4.5 hrs: 9 - (4.5 * 1) = 4.5"
candle B after 4.5 hrs: 9 - (4.5 * 1.5) = 9 - 6.75 = 2.25"