please solve this :

let y1(t) be the height of the candle one so y1(t) = h - (ht) / 6 where h is the initial height of the candle.

similarly y2(t) = h - (ht) / 8

now we have y1(t) = 1/2 y2(t)

on solving this we get t=4hrs and 48 mins.