Tina mixes water , teapowder,sugar and milk.
Leena mixes water,teapowder,sugar and milk and keeps it for boiling. Whose change is irreversible ?

Answer: B. Leena

The correct answer is B. Leena.
Tina's mixture is a physical combination. While difficult, the components (like sugar and water) could technically be separated through physical means like evaporation.
Leena's process involves boiling, which causes a chemical change. The heat causes the tea leaves to release their essence and the milk proteins to react, creating a new substance (liquid tea) that cannot be turned back into its original separate ingredients.

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