How many words can be formed by using all letters of the word ‘DOHA’ ?  Choose the correct choice from the following choices:	A) 12	B) 42	C) 24	D) 21	E) 120
Solution   The word DOHA contains 4 different letters.   Required number of words = 4P4 = 4 ! = (4 x 3 x 2 x 1) = 24   Answer 24
<result>C</result>
How many words can be formed by using all letters of the word ‘DOHA’ ?