Correct Answer:
B. (B) 575 kg
To determine the total quantity of mixture required, we need to understand that the 69 kg of copper represents 12% of the total mixture. Let 'X' be the total mass of the mixture in kg. The problem can be set up as a simple percentage equation: 12% of X = 69 kg.
To solve for X, we convert the percentage to a decimal: 0.12. So, the equation becomes 0.12 * X = 69. Dividing both sides by 0.12 gives us X = 69 / 0.12. Performing this calculation, X = 575 kg. Therefore, 575 kg of the mixture is required to obtain 69 kg of copper. Options (A) 424 kg and (C) 828 kg are incorrect as they do not satisfy the given percentage relationship, likely resulting from miscalculations or incorrect application of the percentage concept.