A container holding 64 litres is full of milk. 16 litres of the liquid is drawn off and replaced by water, and this process is repeated two more times. Find the quantity of water in the container now.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 37 litres
Each time 16 of the 64 litres are taken out, one quarter of the milk present goes out, so the milk left is multiplied by \(\frac{3}{4}\) at every step. The process is done three times in all.
After the 1st replacement: milk \(\displaystyle =64\times\frac{3}{4}=48\) litres
After the 2nd: milk \(\displaystyle =48\times\frac{3}{4}=36\) litres
After the 3rd: milk \(\displaystyle =36\times\frac{3}{4}=27\) litres
Water \(=64-27=37\) litres
The container now has 37 litres of water (and 27 litres of milk).