An algebra problem by Rishabh Bhardwaj

Algebra Level 2

Two candles of the same length are lighted at the same time.The first is consumed in 6 hours and the second in 4 hours.Assuming each candle burns at a constant rate,in how many hours after being lighted was the first candle twice the length of the second.

2 hour 1 hour 3 hours 5 hours

Rishabh Bhardwaj by Rishabh Bhardwaj , 25, India

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Department 8
Jul 14, 2015

We Know the first candle will burn in 6 hours and other in 4 hours.

Let x x be the time after the 6 hour candle's length is twice the length of 4 hour candle.

  • 6 hour candle
  • Percentage burned in 6 hours = 100 100
  • Percentage burned in x hours = 100 x 6 \frac { 100x }{ 6 }

  • Length left = 100 − 100 x 6 100-\frac { 100x }{ 6 }

  • 4 hour candle

  • Percentage burned in 4 hours = 100 100
  • Percentage burned in x hours = 25 x 25x
  • Length left = 100 − 25 x 100 - 25x

We have the equations 100 − 100 x 6 = 2 ( 100 − 25 x ) 100-\frac { 100x }{ 6 } =2(100-25x) x = 3 \boxed{x=3}

3 Helpful 0 Interesting 0 Brilliant 0 Confused

This question was very easy

Abcde Uuuooo - 1 year, 9 months ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...