A box contains 2 white balls, 3 black balls and 4 red balls. What is the number of ways of drawing 3 balls from the box with <strong>AT LEAST</strong> one black ball?
- A. 84
- B. 72
- C. 64 ✓
- D. 48
Correct Answer: C. 64
Explanation
Total number of balls is 9. The number of ways to draw 3 balls without any condition is C(9,3) = 84. The number of ways to draw 3 balls such that none is black is C(6,3) = 20. The number of ways to draw at least one black ball is 84 - 20 = 64.
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