Teacher:Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
Teacher: Now, understand the problem? Solve this instance: Problem: from a container having pure milk, 20 % is replaced by water and the process is repeated thrice. at the end of the third operation, the milk is ?
Options: a. 45 %, b. 49.6 %, c. 51.2 %, d. 55 %, e. 60.3 %
Student:
c