A drum contains 50 litres of pure milk. 5 litres are removed and replaced with water, and this is repeated once. How much water does the drum now contain?
Correct answer B. 9.5 litres
Explanation
Each operation keeps 9/10 of the milk. Milk left = 50 x (9/10)^2 = 40.5 litres, so water = 50 - 40.5 = 9.5 litres.
Answer checked How we write and check questions
Discussion