A 3-inch candle burns down in 6 hours. Assuming the candles are the same thickness and make (that is, directly proportional), how long would it take a 4-inch candle to burn down?

Answer 1

Since the candles are of the same make and thickness, you can assume the rate of burning is constant. This means that the time it takes for a candle to burn is directly proportional to the length of the candle.

A 3-inch candle takes 6 hours to burn down completely, so you can set up a proportion to find out how long it would take a 4-inch candle to burn.

3 inches / 6 hours = 4 inches / x hours

Now, solve for x:

(3 inches / 6 hours) = (4 inches / x hours)
3/6 = 4/x
3x = 4 * 6
3x = 24
x = 24 / 3
x = 8

So, a 4-inch candle would take 8 hours to burn down completely.