Question 1208637
<pre>
CANDLE          BURN RATE      TIME         LENGTH of CANDLE

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

Second          d/3             x             d-(d/3)x
</pre>
Question seems to need the "length of candles" to be as {{{d-(d/4)x=2(d-(d/3)x)}}}.


If divide left and right by d, then  {{{1-x/4=2(1-x/3)}}};

{{{1-x/4=2-2x/3}}}

{{{-x/4=1-2x/3}}}

{{{2x/3-x/4=1}}}

multiply left and right sides by 12;

{{{8x-3x=12}}}

{{{5x=12}}}

{{{x=12/5}}}
and this is 2 and two-fifths hours


{{{2&2/5=2&24/60}}} or two hours twenty-four minutes.