Question:
You have 2 candles and matchbox.
Each candle take exactly 30 minutes to burn from one end to another end.
How could you burn 2 candles within 45 minutes if you don't have stopwatch?
Step1: Burn one candle upto 30 minutes.
Step2: Burn another candle both sides it takes 15 minutes to burn. So total time is 45 minutes.