There are two tanks A & B with same capacity of 20 litres. If the water inflow rate (speed) in Tank A is 2 litres per hour & in Tank B is 4 litres per hour. How much longer tank A takes to fill than Tank B? Choose the correct choice from the following options:
A) 4 hours B) 5 hours C) 3 hours D) 2 hours E) 1 hour
Time taken for Tank A to fill = 20/2= 
<gadget id="calculator">20/2</gadget>
<output>10</output>
10 hours   Time taken for Tank 5 hours to fill= 20/4= 
<gadget id="calculator">20/4</gadget>
<output>5</output>
5 hours   So tank A takes 5 more hours to fill   Answer : 5 hours
<result>B</result>
There are two tanks A & B with same capacity of 20 litres. If the water inflow rate (speed) in Tank A is 2 litres per hour & in Tank B is 4 litres per hour. How much longer tank A takes to fill than Tank B?