Choose the correct answer. If nC12 = nC8 , then n is equal to. - Vidyadip

MCQ

Choose the correct answer.
If ⁿC₁₂=ⁿC₈ , then n is equal to.

A
20
B
12
C
6
D
30

✓

Answer

20

Solution:

Give that $^\text{n}\text{C}_{12}=\ ^\text{n}\text{C}_8[\because\ ^\text{n}\text{C}_\text{r}=\ ^\text{n}\text{C}_\text{n-r}]$

$^\text{n}\text{C}_{12}=\ ^\text{n}\text{C}_\text{n-8}$

$\therefore\text{n}-8=12\Rightarrow\text{n}=12+8=20$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from Permutation and Combinations→Permutation and Combinations — all question types→MATHS STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

If OP makes 4 revolutions in on second the angular velocity in radians per seconds is:

$\pi$
$2\pi$
$4\pi$
$8\pi$

If A = (6, 7, 8, 9), B = (4, 6, 8, 10) and C = {x : x $\in$ N : 2 < x ≤ 7} ; find: A - B

The value of $ (126)^{\frac{1}{3}}$ up to three decimal places is:

Choose the correct answer.
Equation of a circle which passes through (3, 6) and touches the axes is:

Equation of the parabola having focus (3, 2) and Vertex (-1, 2) is:

If in an infinite G.P., first term is equal to 10 times the sum of all successive terms, the its common ratio is:

The coefficients of the expansions are arranged in an array. This array is called ………

Derivative of $x^n$ is equal to :

If a represents the number of permutations of (x + 2) things taken together b represents the number of permutation of 11 things taken together out of x things, and c represents the number of permutation of(x – 11)things taken together so that a = 182, bc = then x is equal to:

$\cos (x+iy)$is equal to [RPET 2001]