SOLUTION: Hi
2 candles A and B. Candle A of a larger diameter was placed on a table. Candle B of a smaller diameter was placed on a 6cm stand so tgat it has the same height as A.
Both we
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2 candles A and B. Candle A of a larger diameter was placed on a table. Candle B of a smaller diameter was placed on a 6cm stand so tgat it has the same height as A.
Both we
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Question 1126342: Hi
2 candles A and B. Candle A of a larger diameter was placed on a table. Candle B of a smaller diameter was placed on a 6cm stand so tgat it has the same height as A.
Both were lit at 11.45. Candle A and B burnt down to a height marked H at 15.15 and 16.45 respectively. The rate of burning for each candle was constant throughout.
Upon reaching height H candle A took 7 hours to burn out while B took 8 hours. Find the original height of A.
thanks
You can put this solution on YOUR website! use rate * time = distance
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let r1 be the rate for candle A and r2 be the rate for candle B
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both candles begin by buring a distance of x
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time candle A takes to burn distance x is 14.75 - 11.45 = 3.5 hours
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time candle B takes to burn distance x is 16.45 - 11.45 = 5 hours
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then we have
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r1 * 3.5 = x
r2 * 5 = x
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r1 * 7 = H
r2 * 8 = H -6
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using the above equations, we know
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r1 = x/3.5 and r1 = H/7
r2 = x/5 and r2 = (H-6)/8
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therefore
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x/3.5 = H/7
7x = 3.5H
x = 3.5H/7
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x/5 = (H-6)/8
8x = 5H -30
x = (5H -30)/8
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3.5H/7 = (5H -30)/8
28H = 35H -210
7H = 210
H = 30
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x = 3.5*30/7 = 15
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Original height of candle A = 30 +15 = 45 cm
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