Question:
A box contains 2 white balls, 3 black balls and 4 red balls. In how many ways can 3 balls be drawn from the box, if at least one black ball is to be included in the draw?
[A].32
48
64
96
A box contains 2 white balls, 3 black balls and 4 red balls. In how many ways can 3 balls be drawn from the box, if at least one black ball is to be included in the draw?
[A].
[B].
[C].
[D].
Answer: Option C
Explanation:
We may have(1 black and 2 non-black) or (2 black and 1 non-black) or (3 black).
| Required number of ways | = (3C1 x 6C2) + (3C2 x 6C1) + (3C3) | |||||||||||||
|
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| = (45 + 18 + 1) | ||||||||||||||
| = 64. |