Ask Questions, Get Answers

Home  >>  CBSE XI  >>  Math  >>  Permutations and Combinations

A bag contains six white marbles and five red marbles.Find the number of ways in which four marbles can be drawn from the bag if they can be of any colour

$\begin{array}{1 1}(A)\;300\\(B)\;310\\(C)\;320\\(D)\;330\end{array} $

1 Answer

  • $C(n,r)=\large\frac{n!}{r!(n-r)!}$
White marbles =6
Red marbles =5
Total no of marbles =11
No of ways in which 4 marbles can be drawn =$11C_4$
$\Rightarrow \large\frac{11!}{4!7!}$
$\Rightarrow \large\frac{11\times 10\times 9\times 8\times 7!}{4\times 3 \times 2\times 1\times 7!}$
$\Rightarrow 330$ ways
Hence (D) is the correct answer.
answered May 15, 2014 by sreemathi.v

Related questions