Subject
Quantitative Aptitude
Topic
Permutation & Combination
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 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?
ক)
32খ)
48গ)
64ঘ)
96Explanation
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) = {3 x (6 x 5)/( 2 x 1)} + [{(3 x 2)/( 2 x 1)} x 6] + 1 = (45 + 18 + 1) = 64.Related questions
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