Maths question – Rate, candles burning

Maths tip:

Here’s another similar question to the previous maths post. Let me know if there are any other methods to solve this!

Q: Two candles of the same height are lit at the same time. The first candle takes 5h to burn completely. The second candle takes 4h to burn completely. If each candle burns at a constant rate, how long does it take, in hours, for the height of the first candle to be four times that of the second candle?