Question

Evaluate the expression 18C4

Answer 1

3,060

Explanation:

Given:

18C4

nCr=n! / r!(n-r)!

=18! / 4!(18-4)!

18!=18*17*16*15*14*13*12*11*10*9*8*7*6*5*4*3*2*1

=6,402,373,705,728,000

4!=4*3*2*1

=24

(18-4)!=14!

=14*13*12*11*10*9*8*7*6*5*4*3*2*1

=87,178,291,200

18! / 4!(18-4)!

=6,402,373,705,728,000 / 24*87,178,291,200

=6,402,373,705,728,000 / 2,092,278,988,800

=3,060