Answer
$ 210$ ways
Work Step by Step
A permutation from a group of items occurs when no item is used more than once and the order of arrangement makes a difference.
The number of permutations possible if $r$ items are taken from $n$ items is
${}_{n}P_{r}=\displaystyle \frac{n!}{(n-r)!}$.
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Arrangements: order is important.
There are n=7 distinct letters (no duplicates) from which r=4 are taken.
The formula ${}_{n}P_{r}=\displaystyle \frac{n!}{(n-r)!}$ applies.
${}_{7}P_{4}=\displaystyle \frac{7!}{3!}=7\times 6\times 5=$
$= 210$ ways