CAT 2020 Permutations and Combinations Question (Medium)

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?

Optima Learn · Accepted Answer

The easiest approach for at least one black is to subtract the no-black case from the total. Understanding the Setup The box has 2 white 3 black 4 red 9 balls 3 balls are drawn, and at least one must be black. Analyzing the Calculation Total ways to choose 3 from 9 C 9,3 84. Ways with no black ball

CAT 2020 Permutations and Combinations — Previous Year Question

CAT 2020

Quantitative

Permutations and Combinations

Medium

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