How many different words can be formed by jumbling the letters in the word $MISSISSIPPI$ in which no two $S$ are adjacent $?$
$8.^6C_4$
$6.7. ^8C_4$
$6.8. ^7C_4$
$7. ^6C_4. ^8C_4$
How many words can be made from the letters of the word $BHARAT$ in which $ B $ and $H$ never come together
$\sum \limits_{ k =0}^6{ }^{51- k } C _3$ is equal to
The number of $4-$letter words, with or without meaning, each consisting of $2$ vowels and $2$ consonants, which can be formed from the letters of the word $UNIVERSE$ without repetition is $.........$.
$^{47}{C_4} + \mathop \sum \limits_{r = 1}^5 {}^{52 - r}{C_3} = $
$^n{C_r}\,{ \div ^n}{C_{r - 1}} = $