Question

if nc9 = nc11
,find the value of n

Answer 1

Answer:

yjxfjyfzzutdiufxxougzjgccjyxxkugiuxgixyfyzfiyfziyfz

Answer 2

$\displaystyle \sf{If \: \: {}^{n} C_9 ={}^{n} C_{11} \: \: then \: \: n = 20 }$

Given :

$\displaystyle \sf{ {}^{n} C_9 ={}^{n} C_{11} }$

To find :

The value of n

Formula :

$\displaystyle \sf{If \: \: {}^{n} C_p ={}^{n} C_{q} \: \: then \: n = p + q }$

Solution

Step 1 of 2 :

Write down the given equation

Here the given equation is

$\displaystyle \sf{\: \: {}^{n} C_9 ={}^{n} C_{11} }$

Step 2 of 2 :

Find the value of n

We know that

$\displaystyle \sf{If \: \: {}^{n} C_p ={}^{n} C_{q} \: \: then \: n = p + q }$

Thus we get

$\displaystyle \sf{\: \: {}^{n} C_9 ={}^{n} C_{11} }$

$\displaystyle \sf{\implies \: n = 9 + 11 }$

$\displaystyle \sf{\implies \: n = 20}$

Hence the required value of n = 20