Explanation
We are required to determine the value of the following:
[tex]_{15}C_3[/tex]
This is achieved thus:
We know that the combination formula is given as:
Therefore, we have:
[tex]\begin{gathered} _{15}C_3=\frac{15!}{3!(15-3)!} \\ _{15}C_3=\frac{15!}{3!12!} \\ _{15}C_3=\frac{15\cdot14\cdot13\cdot12!}{3!12!} \\ _{15}C_3=\frac{15\cdot14\cdot13}{3!}=\frac{15\cdot14\cdot13}{3\cdot2\cdot1} \\ _{15}C_3=5\cdot7\cdot13 \\ _{15}C_3=455 \end{gathered}[/tex]
Hence, the answer is:
[tex]455[/tex]
