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JEE MATHEMATICS MCQ: COMBINATIONS

1 Easy

1 of 1

Application +4 | -1

If

{ }^n C_{r-1}=36,{ }^n C_r=84

and

{ }^n C_{r+1}=126

, then the value of

r

is equal to

View answer and explanation

Correct option: C

3

Option C (3) is correct because by setting up ratios of consecutive combinations and solving the resulting system of equations, we find that r = 3.

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n