Question

Calculate. 12C4 Please help!

Answer 1

Answer:

495

Step-by-step explanation:

${12 \: }^{c} \: 4 = \frac{12!}{4!(12 - 4)!} \\ = \frac{12!}{4! \times 8!} \\ = \frac{12 \times 11 \times 10 \times 9 \times 8!}{4! \times 8!}$

canceling 8! from both numerator and denominator.

$\frac{12 \times 11 \times 10 \times 9}{4 \times 3 \times 2 \times 1} \\ = 11 \times 9 \times 5\\ = 495$

Factorial of an integer, in mathematics, is the product of all positive integers less than or equal to the given positive integer.

Factorial of a number is denoted by placing an exclamation mark behind the number

Answer 2

$\quad\quad\quad\quad \net\net \net\netu\internetu\y\menyaa \la\la\la\la\\\\\\\\\\\\\dddddddddd\\\FFFFFFFF\\\\\\\\\\\\\ \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\displaystyle\ \Large \boldsymbol{} _{12}C_4=\frac{12!}{4!(12-4)!} =\frac{12!}{4!\cdot8!} =\frac{12\cdot11\cdot10\cdot9\cdot8!\!\!\!\!\!\diagup}{4!\cdot8! \!\!\!\!\!\diagup} = \\\\\\\frac{12\!\!\!\!\!\diagup\cdot11\cdot10\cdot9}{24\!\!\!\!\!\diagup_{\ \ 2}}= \frac{11\cdot10\cdot9}{2} =\boxed{495}$