Evaluate ⁿ⁺¹C_n-2 If n =15

Craig Duffy

9 years ago

dats a very long and confusing method.. if we all kW d formulae for combination,den we re gud to go.



( n+1)

C

(n-1)



since,n=15. Hence,substitute n for 15.



( 15+1)

C

( 15-2)



16

C

13

.using d formulae



16!/ 13!(16-13)!





= 16!/ 13!3!



after cancellation,we HV;



16×15×14/3×2



= 3360/6



=560

Sacrifice

9 years ago

B is my own answer oooo

Markjay

11 years ago

B is the right answer

damilare3043

10 years ago

The answer is 210











And 210 is not in the option

chibelinda

9 years ago

D is d answer

josevin

2 years ago

The question is wrongly written

Sacrifice

9 years ago

The answer is 560.