We have to evaluate the expression C22
Solution
To evaluate the expression C22 we use the following formula
nCr =n! / r! (n – r)!
n = 2
r = 2
Substitute n and r values in above formula
nCr =n! / r! (n – r)!
C22= 2! / 2! (2-2)!
C22= 2! / 2! (0)!
Find the factorial for 2!, 2! & 0!, substitute the corresponding values in the below expression and simplify. We have learnt that 0! = 1
=2 X 1 / (2 X 1) (1)
= 2/ (2 )
= 2 / 2
= 1
C22= 1
Answer
C22= 1