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JEE MATHEMATICS MCQ: PERMUTATIONS

1 Easy

1 of 1

Application +4 | -1

If

{ }^{15} C_{{r}+1}:{ }^{15} C_{3 {r}}=3: 11

, then value of

r

is:

View answer and explanation

Correct option: B

3

Option B (3) is correct because substituting r=3 into the ratio

{}^{15} C_{{r}+1}:{}^{15} C_{3 {r}}=3: 11

satisfies the equation after simplifying the combinations.

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