Question

35. Two candles of the same height are lighted at the same time. The first is consumed in 8 hours and the
second in 6 hours. Assuming that each candle burns at a constant rate, in how many hours after being
lighted, the ratio between the first and second candles becomes 2:1.
(1) 2 hours 24 minutes
(2) 4 hours
(3) 1 hour 12 minutes
(4) 4 hours 48 minutes
(5) None of these
7​

Answer 1

Answer:

(4)

Step-by-step explanation:

Let h be the height of the candle

speed of first candle = h/8

speed of second candle = h/6

how many hours after bring lit was the first candle twice the height of the second?

Candle at that time (t)

r =h -(h/6)t

At the time (t),the height of the first candle must be 2r

2r =h -(h/8)t

2(h -(h/8)t

2(h -(h/6)t) =h -(h/8)t

2h -(2/6)ht =h -(1/8)h

2 -(2/6)t =1 -(1/8)t

t(2/6-1/8) =1

t = _16-6_

48