How many words can be formed by using all letters of the word ‘LONDON’ ?  Choose the correct option:
A) 120 B) 320 C) 420 D) 620 E) 720
Solution   The word LONDON contains 6 different letters.   Required number of words = 6P6 = 6 ! = (6 x 5 x 4 x 3 x 2 x 1) = 720   Answer 720
<result>E</result>
How many words can be formed by using all letters of the word ‘LONDON’ ?