Explanation:

- Start with a 64-litre mixture where milk and water are in a 15:1 ratio.

- This means there are 60 litres of milk and 4 litres of water since \( \frac{15}{16} \times 64 = 60 \) and \( \frac{1}{16} \times 64 = 4 \).

- When 24 litres of the mixture is removed, calculate what's left: \( \frac{15}{16} \times 24 = 22.5 \) litres of milk and \( \frac{1}{16} \times 24 = 1.5 \) litres of water are removed.

- Thus, 60 - 22.5 = 37.5 litres of milk and 4 - 1.5 = 2.5 litres of water remain.

- Add 5 litres of milk and 5 litres of water to what’s left.

- Now, there's a total of 42.5 litres of milk (37.5 + 5) and 7.5 litres of water (2.5 + 5).

- The difference between milk and water is 42.5 - 7.5 = 35 litres.

- The correct option is 3, 35 litres.

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