How many $4$-letter codes can be formed using the first $10$ letters of the English alphabet,if no letter can be repeated?

Find the number of arrangements of the letters of the word $INDEPENDENCE$. In how many of these arrangements do the words begin with $I$ and end in $P$?

The number of all possible three-letter words that can be formed by choosing three letters from the letters of the word $FEBRUARY$ so that a vowel always occupies the middle place is:

If $a$ denotes the number of permutations of $(x + 2)$ items taken all at a time,$b$ denotes the number of permutations of $x$ items taken $11$ at a time,and $c$ denotes the number of permutations of $(x - 11)$ items taken all at a time. If $a = 182bc$,find the value of $x$.

The number of distinct positive integers that can be formed using $0, 1, 2, 3$,where each integer is used at most once,is equal to

How many $3$-digit numbers can be formed by using the digits $1$ to $9$ if no digit is repeated?