From a cask full of milk 20 liters are taken out of 60 liters and is filled with water This was done...........

Quantitative Aptitude (CDS) Mixture and Alligation

From a cask full of milk, 20 liters are taken out of 60 liters and is filled with water. This was done twice. What is the quantity of milk now left in the cask?

20 liters

32 liters

25 liters

26.67 liters

Explanation:

Since 20 liters are withdrawn = 20 / 60 = 1/3 of the whole .
Quantity of milk after 2nd operation
= 60 × ( 1 – 1/3 ) ^2
= 60 × 2/3×2/3
= 60 × 4/9
= 26.67 liters