Explanation:

- A, B, and C have chocolates in the ratio 3:2:5.

- Let the number of chocolates with A, B, and C be 3x, 2x, and 5x respectively.

- A takes 10 chocolates from B and 20 from C.

- B's chocolates become 2x - 10 after A takes 10 chocolates.

- C's chocolates become 5x - 20 after A takes 20 chocolates.

- The ratio of chocolates between B and C becomes 1:3.

- Hence, (2x - 10)/(5x - 20) = 1/3.

- Solving the equation: 3(2x - 10) = 1(5x - 20)

- This leads to: 6x - 30 = 5x - 20

- Simplifying gives: x = 10.

- So, total chocolates initially = 3x + 2x + 5x = 10x = 100.

- Option 3: 100 is correct.

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