<PRE><B>Question 343880</B>
Candle A and candle B are of the same length.
 Candle A, which is broader, can burn for 5 h
 while Candle B, the thinner candle, can burn for 4 h.
 If both candles are lit at the same time, how long does it take for
 Candle A to be twice as long as Candle B?
:
It would be convenient to choose a length for both candles, say 20 inches
then
Candle A will burn 20/5, 4 in/hr
Candle B will burn 20/4, 5 in/hr
:
Let t = time in hrs when candle A will be twice as long as Candle B
20 - 4t = 2(20-5t)
20 - 4t = 40 - 10t
-4t + 10t = 40 - 20
6t = 20
t = {{{20/6}}}
t = {{{10/3}}} or 3{{{1/3}}} hrs for A to be twice as long as B
:
:
Check solution by finding the length of each after 3.33 hrs
20 - 4(3.33) = 6.67 inches
20 - 5(3.33) = 3.335 inches, confirms our solution</PRE>