Measure time using candle!!

Problem statement: You have two candles that can be burnt from both sides. Each candle takes exactly one hour to get burnt completely. You have to measure 45 minutes with the help of these candles. How will you do it?

Solution: Here, we cannot assume that the candle will burn uniformly. So, we cannot  assume that half the candle will get burnt in half an hour and so on. But, if we can somehow let it burn for half an hour, then we can surely assume that the rest will burn in half hour only.

The solution of this puzzle follows:

First, light one of the candles from both sides. Simultaneously, light the other candle from one side only. Now, the first candle will get exhausted in half an hour only as discussed above. After half hour, the other candle has another half an hour left in it. As soon as first candle gets burnt up completely, light the other end of the second candle. Now, the second candle will get exhausted after another 15 minutes as it will burn at twice the rate.

This is how we can measure 45 minutes using two candles that can be burnt from both the sides.