# There are two water tanks A and B, A is much smaller than B. While water fills at the rate of 1 litre every hour in A, it gets filled up like, 10, 20, 40, 80,160 in tank B. (At the end of first hour, B has 10 litres, second hour it has 20 litres and so on). If tank B is 1/16 filled of the 3 hours, what is total duration of hours required to fill it completely?