# There are two candles of same height one completely burns in 8 hours and one burns in 6 hours. How much time is left for the 8 hour candle when the candle which burn in 6 hours is half its height?

• June 30th, 2013, 12:57 AM
Rhitik
There are two candles of same height one completely burns in 8 hours and one burns in 6 hours. How much time is left for the 8 hour candle when the candle which burn in 6 hours is half its height?
How to do this question?? I am confused it is a very simple question. Why IDK I can't do this.
• June 30th, 2013, 01:15 AM
Lynx_Fox
Homework....if so try to solve and tell us what your thinking.

I'll leave this tip though...many ways to solve it...but easiest probably think of each candle as a separate equation.
• June 30th, 2013, 01:31 AM
Rhitik
Quote:

Originally Posted by Lynx_Fox
Homework....if so try to solve and tell us what your thinking.

I'll leave this tip though...many ways to solve it...but easiest probably think of each candle as a separate equation.

Umm. I tried a lot my answer is coming 5 but the answer is 4.8.:confused:
• June 30th, 2013, 05:02 AM
RedPanda
Quote:

Originally Posted by Rhitik
Umm. I tried a lot my answer is coming 5 but the answer is 4.8.:confused:

I also get an answer of 5 hours.
But I am suspecting that you have not quoted the question exactly/correctly - as it seems to be too 'simple' a question.

For example, here is a similar question:
which is more like the kind of question I would expect.

Could you re-check the question (or maybe post the question verbatim)?
• June 30th, 2013, 05:39 AM
SpeedFreek
The question is badly worded. "How much time is left for the 8 hour candle when the candle which burn in 6 hours is half its height?"

Do they mean the 6 hour candle is half its own original height, or that it is half the height of the 8 hour candle?

The answer is 5 for the first case, but is not 5 for the second case.
• June 30th, 2013, 06:42 AM
Harold14370
Quote:

Originally Posted by SpeedFreek
The question is badly worded. "How much time is left for the 8 hour candle when the candle which burn in 6 hours is half its height?"

Do they mean the 6 hour candle is half its own original height, or that it is half the height of the 8 hour candle?

The answer is 5 for the first case, but is not 5 for the second case.

True but the answer for the second case isn't 4.8, either, so there's still something wrong. In the second case, 4.8 hours is the time the candles have burned, not the time left on the 8-hour candle.

In 4.8 hours the 8 hour candle has burned down to (8-4.8)/8=3.2/8=0.4 of the original height, and the 6 hour candle is (6-4.8)/6=0.2. This is where the 6-hour candle is half the remaining height of the 8-hour candle.