Question

What is the value of 15c13 ?

a. 30

b. 15

c. 210

d. 105?

Answer 1

Answer:

105

Step-by-step explanation:

it can be written as      $\frac{15!}{13! .2!}$

from where it turns out to be 105

                       

Answer 2

Answer:

$_{13}^{15}\txterm{C}=105$

Step-by-step explanation:

we have to find the value of

$_{13}^{15}\txterm{C}$

$\text{the formula to find }_{r}^{n}\txterm{C}$

$_{r}^{n}\txterm{C}=\frac{n!}{r!(n-r)!}$

$_{13}^{15}\txterm{C}=\frac{15!}{13!(15-13)!}$

$=\frac{15\times 14\times 13!}{13!\times 2!}=15\times 7=105$

Option d is correct