Comment
Share
Q)

# In how many number of ways can 10 students be divided into three teams,one containing four students and the other three?

$\begin{array}{1 1}(A)\;400\\(B)\;700\\(C)\;1050\\(D)\;2100\end{array}$

• $C(n,r)=\large\frac{n!}{r!(n-r)!}$
Required no. of ways =$\large\frac{10C_4\times 6C_3\times 3C_3}{2!}$
$10C_4=\large\frac{10!}{4!6!}$
$\Rightarrow \large\frac{10\times 9\times 8\times 7\times 6!}{4\times 3\times 2\times 6!}$$=210 6C_3=\large\frac{6!}{3!3!} \Rightarrow \large\frac{6\times 5\times 4\times 3!}{3!0!}$$=1$
$\Rightarrow \large\frac{210\times 20\times 1}{2}$
$\Rightarrow 2100$