Question

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

Answer 1

Since repeatition is not allowed,

There are 10 ways for choosing first letter,

9 ways for choosing second letter,

8 ways of choosing third letter and

7 ways of choosing fourth letter

Hence total no. of 4 letter word

$$=10×9×8×7=5040$$