Two candles of the same height are lighted at the same time. The first is consumed in 6 hours and the second in 4 hours. Assuming that each candle burns at a constant rate, in how many hours after being lighted, was the first candle was twice the height of the second?
1) 3.5 hrs
2) 2 hrs
3) 4 hrs
4) 3 hrs
5) 2.5 hrs

• 6*4(2-1)/2*6-4=3hrs
• 8 years agoHelpfull: Yes(2) No(3)
• let the height of each candle is 12 metres.
  rate of decrease in height in first candle is 12/6 =2m/hr
  rate of decrease in height in second handle is 12/4=3m/hr
  so we have to find the time after which the remaining height of candle 1 is twice of candle 2
  So,
  12-2n=2(12-3n)
  24-6n=12-2n
  12=4n
  n=3
  So after 3 hrs the height of candle 1 is x2 of candle 2
• 7 years agoHelpfull: Yes(1) No(0)
• As first candle was twice the height of second so 2:1
  then (1-(t/6))/(1-(t/4))=2/1
  (24-4t)/(24-6t)=2/1
  24-4t=48-12t
  24=8t
  t=3hrs
• 5 years agoHelpfull: Yes(1) No(0)