3 containers A, B and C contain water, milk and acid respectively in equal quantities. 10% of the content of A is taken out and poured to B. Then same percentage from B is transferred to C, from which again the same percentage is transferred to A. Find the percentage of milk in container A at the end of the process.

Track the milk through each transfer: initially A has 100 water, B has 100 milk. After 10% of A (10 water) moves to B, B has 110 total (100 milk + 10 water). When 10% of B (11 units) moves to C, it contains 10 milk and 1 water. Finally, 10% of C (11.1 units) moves back to A. The milk reaching A is 11 × 10/111 = 0.99 units out of A's final 101.1 units, giving 0.98%. This successive percentage problem requires tracking composition changes at each step.