There are two water tanks A and B, A is much smaller than B. While water fills at the rate of one 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, and so on). If tank B is 1/16 filled after 4 hours, what is the total duration required to fill it completely?

a) 8hrs b) 25 hrs c) 5 hrs d) 27 hrs

• Ans is a.)8hrs
  let total duration be x
  so x/16 in 4hrs
  x/16*2 in 5hrs ( we are multiplying by 2 bcoz tank B gets doubled)
  x/8*2 in 6hrs
  x/4*2 in 7hrs
  x/2*2 in 8hrs
  we get x now which is total duration.
• 12 years agoHelpfull: Yes(5) No(1)