A container has a capacity of 20 gallons and is full of spirit. 5 gallons of spirit is drawn out and the container is again filled with water. This process is repeated 5 times. Find how much spirit is left in the resulting mixture finally? Choose one:  A) (257/525) gallons  B) 1.5552 gallons  C) 1.5 gallons  D) 1.25 gallons  E) None of these
There is a direct formula to calculate such repetition:   Left QTY / Orig QTY = ( (Orig QTY - Rep QTY) / Orig QTY )^n   where n is number of times mixing done:   Left QTY / 20 = (20 -5)^5 / 20^5   Left QTY = 20 (15/20)^5   Left QTY = 20 ( 3/5 )^5   Left QTY = 1.5552   Answer is 1.5552 gallons
<result>B</result>
A container has a capacity of 20 gallons and is full of spirit. 5 gallons of spirit is drawn out and the container is again filled with water. This process is repeated 5 times. Find how much spirit is left in the resulting mixture finally?