What is the number of ways of choosing $4$ cards from a pack of $52$ playing cards? In how many of these
are face cards,
There will be as many ways of choosing $4$ cards from $52$ cards as there are combinations of $52$ different things, taken $4$ at a time. Therefore
The required number of ways $=\,\,^{52} C _{4}=\frac{52 !}{4 ! 48 !}=\frac{49 \times 50 \times 51 \times 52}{2 \times 3 \times 4}$
$=270725$
There are $12$ face cards and $4$ are to be selected out of these $12$ cards. This can be done in $^{12} C _{4}$ ways.
Therefore, the required number of ways $=\frac{12 !}{4 ! 8 !}=495$
The total number of different combinations of one or more letters which can be made from the letters of the word ‘$MISSISSIPPI$’ is
If $x,\;y$ and $r$ are positive integers, then $^x{C_r}{ + ^x}{C_{r - 1}}^y{C_1}{ + ^x}{C_{r - 2}}^y{C_2} + .......{ + ^y}{C_r} = $
$^n{C_r}{ + ^{n - 1}}{C_r} + ......{ + ^r}{C_r}$ =
If $^8{C_r}{ = ^8}{C_{r + 2}}$, then the value of $^r{C_2}$ is
What is the number of ways of choosing $4$ cards from a pack of $52$ playing cards? In how many of these
two are red cards and two are black cards,