Question

What is the value of 15C13

Answer 1

HEY MATE,,,,


HERE IS YOUR ANSWER..... :)


The value of 15C13.

SOLUTION:

15C3 + 15C13

= 15C3 + 15C2

= 15×14×13 upon 3×2 + 15×14 upon 2

= 455 + 105 = 560 is the answer.....


NOTE: Using the formula, nCr + nC ( r-1 ) = ( n+1 ) Cr, we can also do as

= 16C3 = 16×15×14 upon 3×2 = 560.


HOPE THIS HELPS YOU.... .

Answer 2

$\displaystyle \sf{ {}^{15}C_{13} } = 105$

Given :

$\displaystyle \sf{ {}^{15}C_{13} }$

To find :

The value of the expression

Formula :

$\displaystyle \sf{ {}^{n}C_{r} = \frac{n!}{r! \: (n- r)!}}$

Solution :

Step 1 of 2 :

Write down the given expression

The given expression is

$\displaystyle \sf{ {}^{15}C_{13} }$

Step 2 of 2 :

Simplify the given expression

$\displaystyle \sf{ {}^{15}C_{13} }$

$\displaystyle \sf{ = \frac{15!}{13! \: (15 - 13)!} }$

$\displaystyle \sf{ = \frac{15 !}{13! \: 2!} }$

$\displaystyle \sf{ = \frac{15 \times 14 \times 13 !}{13! \: 2!} }$

$\displaystyle \sf{ = \frac{15 \times 14 }{ 2!} }$

$\displaystyle \sf{ = \frac{15 \times 14 }{ 2 \times 1} }$

$\displaystyle \sf{ = 15 \times 7 }$

$\displaystyle \sf{ = 105 }$