Q. 7

# Mark the correct alternative in the following:

If , then *n* =

A. 20

B. 12

C. 6

D. 30

Answer :

n = 12 + 8 ( ^{n}C_{x =} ^{n}C_{y} ⇒ n = x + y or x = y )

n = 20

Rate this question :

How useful is this solution?

We strive to provide quality solutions. Please rate us to serve you better.

Related Videos

Challenging Quiz on P&C | Test Yourself55 mins

Permutations & Combinations | Analyze your learningFREE Class

Lecture on Combinations49 mins

Check Your progress Part 2| Interactive Quiz: Permutation & Combination54 mins

Understand Permutations like never before60 mins

Interactive Quiz on Division and distribution of objects17 mins

Combinations - BOX & GAP Method38 mins

Interactive Quiz on Combinations50 mins

Interactive Quiz on Combinations-0253 mins

Circular permutations61 mins

Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Expertsview all courses

Dedicated counsellor for each student

24X7 Doubt Resolution

Daily Report Card

Detailed Performance Evaluation

RELATED QUESTIONS :

Prove that the product of 2n consecutive negative integers is divisible by (2n)!

RD Sharma - MathematicsThere are 10 lamps in a hall. Each one of them can be switched on independently. Find the number of ways in which the hall can be illuminated.[Hint: Required number = 210 – 1].

Mathematics - ExemplarIf ^{n+1}C_{r+1} : ^{n}C_{r} = 11 : 6 and ^{n}C_{r} : ^{n–1}C_{r–1} = 6 : 3, find n and r.

If ^{n}C_{r–1} = 36, ^{n}C_{r} = 84 and ^{n}C_{r+1} = 126, find r.

Fill in the Blanks

If ^{n}P_{r} = 840, ^{n}C_{r} = 35, then r = ______.

The number of ways in which a team of eleven players can be selected from 22 players always including 2 of them and excluding 4 of them is

Mathematics - Exemplar