1.  How many 4-letter words with or without meaning, can be formed out of the letters of the word, 'LOGARITHMS', if repetition of letters is not allowed?
A. 40
B. 400
C. 5040
D. 2520

Answer: Option C

Explanation:

'LOGARITHMS' contains 10 different letters.

Required number of words = Number of arrangements of 10 letters, taking 4 at a time.

= 10P4
= (10 x 9 x 8 x 7)
= 5040.