(63)
From the question, we are to evaluate the given binomial coefficient.
(90)
( 2 )
Using the formula:
(n) = n! = n! = 1
(0) 0!(n - 0)! 1 * n!
inputting into the formula
90C2 = 90!
2!(90-2)!
90C2 = 90!
2!(88)!
90C2 = 14857159644817614973095227336
2 * 18548264225739843911479684564
90C2 = 14857159644817614973095227336
3709652845179687822959369129
90C2 = 4005