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Question
Find the number of ways of dividing 20 objects in three groups of sizes 8, 7, and 5.
Solution
Select 8 object out of 20 in 20C8 ways
Select 7 object from the remaining 12 in 12C7 ways and 5 objects form the remaining 5 in 5C5 ways
Required number is = 20C8 × 12C7 × 5C5
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