There are two candles of equal lengths and of different thickness. The thicker one lasts of six hours. The thinner 2 hours less than the thicker one. Ramesh lights the two candles at the same time. When he went to bed he saw the thicker one is twice the length of the thinner one. How long ago did Ramesh light the two candles .

• Both are Equal length: L
  Thick's burning rate: L/6
  Thin's burning rate: L/4
  After X hours (at bed time) of burning, remaining lengths:
  Thick: L-(LX/6) and Thin: L-(LX/4)
  But, at X hours, thick is twice as long as thin. i.e.:
  L-(LX/6)=2[L-(LX/4)]
  1-(X/6)=2-(X/2)
  Solve for X and get 3.
• 11 years agoHelpfull: Yes(26) No(2)
• There are two candles of equal lengths and of different thickness. The thicker one lasts of six hours. The thinner 2 hours less than the thicker one. Ramesh lights the two candles at the same time. When he went to bed he saw the thicker one is twice the length of the thinner one. How long ago did Ramesh light the two candles .
  
  Solution:
  
  Given: Thicker one lasts 6 hours.
  SO AFTER EACH HOUR, (1/6) of the candle is melted
  Thinner one lasts 2 hours lesser than thicker candle.i.e it lasts 4 hours
  SO AFTER EACH HOUR, (1/4) of the candle is melted
  
  AFTER n HOUR REMAINING THICKER CANDLE REMAINING THINNER CANDLE
  1 (5/6) (3/4)
  2 (4/6) (2/4)
  3 (3/6) (1/4)
  Here we can notice that after 3 hours the remaining portion of thicker candle is(3/6) which is 0.5 or HALF. Remaining portion of thinner candle is (1/4) which is 0.25 or QUARTER.
  HALF= 2(QUARTER).
  Therefore, The answer is 3 hours
• 11 years agoHelpfull: Yes(14) No(0)
• Thicker candle - 6hr
  thinner candle -4hr
  lcm of (6,4)=12
  thinner candle burn in 1 hour= 3part
  thicker candle burn in 1 hour= 2part
  in 1 hr length of candle left : (thicker,thinner):(10,9)
  in 2 hr (8,6)
  in 3 hr (6,3)
  so, 3 hr Ans
  
• 9 years agoHelpfull: Yes(5) No(0)
• PLEASE MAKE SURE THAT I HAD TABULATED IN THE SOLUTION GIVEN ABOVE. After n hour, remaining thicker candle, remaining thinner candle are three separate columns.
  The values 1, (5/6) and (3/4) all belong to the 3 columns respectively
• 11 years agoHelpfull: Yes(3) No(0)
• 3hrs
  1-h/6 = (1-h/4)2
  
• 9 years agoHelpfull: Yes(1) No(0)
• thinnner one burns for 4hrs..
  assume thinner one burned 3/4th
  so,1/4 is remaining
  double length is 1/2i.,e thicker one...
  time taken for 3/4 is 3/4 * 4hrs= 3hrs...
  and in 3hrs thickker candle burns half and half will be remaining.....
  so,Ramesh lit the candles for 3 hrs....
• 9 years agoHelpfull: Yes(0) No(0)