We have to evaluate the expression C52
Solution
To evaluate the expression C52 we use the following formula
nCr =n! / r! (n – r)!
n = 5
r = 2
Substitute n and r values in above formula
nCr =n! / r! (n – r)!
C52= 5! / 2! (5-2)!
C52= 5! / 2! (3)!
Find the factorial for 5!, 2! & 3!, substitute the corresponding values in the below expression and simplify.
= 5 X 4 X 3 X 2 X 1 / (2 X 1) ( 3 X 2 X 1)
= 120/ (2 ) (6)
= 120 / 12
= 10
C52= 10
Answer
C52= 10