JEE Exam  >  JEE Questions  >  If nC8 = nC2, then n isa)8b)12c)10d)2Correct ... Start Learning for Free
If nC8 = nC2, then n is
  • a)
    8
  • b)
    12
  • c)
    10
  • d)
    2
Correct answer is option 'C'. Can you explain this answer?
Most Upvoted Answer
If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can...
Explanation:

To solve this problem, we need to use the formula for the combination (nCr), which is given by:

nCr = n! / (r!(n-r)!)

where n is the total number of objects, and r is the number of objects chosen at a time.

Given that nC8 = nC2, we can set up the equation as follows:

n! / (8!(n-8)!) = n! / (2!(n-2)!)

To simplify the equation, we can cancel out the common terms on both sides:

(n-2)! * 8! = (n-8)! * 2!

Now, let's expand the factorials:

(n-2)! * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1 = (n-8)! * 2 * 1

Cancel out the common terms:

8 * 7 * 6 * 5 * 4 * 3 = (n-8)!

We are left with:

8 * 7 * 6 * 5 * 4 * 3 = (n-8)!

Now, let's evaluate the factorial on the left side:

8 * 7 * 6 * 5 * 4 * 3 = 20160

So, we have:

20160 = (n-8)!

To find the value of n, we need to determine the value of (n-8)!. We can do this by finding the factorial of numbers from 1 to 8 until we find a number that is equal to or greater than 20160.

By evaluating the factorials, we find that 8! = 40320, which is greater than 20160. The next factorial, 7!, is equal to 5040, which is less than 20160.

Therefore, n must be greater than 8 but less than 16. The only option that satisfies this condition is option 'C', which is 10.

Hence, the correct answer is option 'C'.
Free Test
Community Answer
If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can...
Given nC8 = nC2
if nCr = nCp
Then either r=p or r=n−p
Thus, nC8 = nC2
8=n−2
10=n
∴ n=10
Explore Courses for JEE exam
If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer?
Question Description
If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer? for JEE 2025 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for JEE 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer?.
Solutions for If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for JEE. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
Here you can find the meaning of If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer?, a detailed solution for If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice If nC8 = nC2, then n isa)8b)12c)10d)2Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice JEE tests.
Explore Courses for JEE exam

Top Courses for JEE

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev