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JEE MATHEMATICS MCQ: COMBINATIONS

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If

a, b

and

r

are positive integers, then value of

{ }^a C_r+{ }^a C_{r-1}{ }^b C_1+{ }^a C_{r-2}{ }^b C_2+\ldots+{ }^b C_r \text { is}

View answer and explanation

Correct option: C

{ }^{a+b} C_r

Option C (

{ }^{a+b} C_r

) is correct because the given expression represents the number of ways to choose r items from a group of a+b items.

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n