Question

How many 4-letter words, with or without meaning, can be formed out of the letters of the word, "LOGARITHMS", if repitition of letters is not allowed ?

Answer 1

There are 10 letters in the word $"LOGARITHMS".$

So, the number of 4-letter word = Number of arrangements of 10 letters, taken 4 at a time

$={10}_{P_4}=\frac{10!}{(10-4)!}=5040$