A 8-inch candle burns down in 4 hours. Assuming the candles are the same thickness and make (that is, directly proportional), how long would it take a 12-inch candle to burn down?
If the 8-inch candle burns down in 4 hours, it burns at a rate of 2 inches per hour (8 inches / 4 hours = 2 inches per hour).
Therefore, a 12-inch candle would burn down in 6 hours (12 inches / 2 inches per hour = 6 hours).