Out of 8 consonants and 5 vowels, how many words of 4 consonants and 3 vowels can be formed?	Pick one.
A) 15000 B) 352800 C) 25200 D) 214000 E) None of these
Solution   Number of ways of selecting (4 consonants out of 8) and (3 vowels out of 5)   nCr=n!/r!(n-r)!   8c4 x 5c3= (8x7x6x5/4x3x2x1)x(5x4x3/3x2x1) =70x10=700   Number of group,each having 4 consonants and 3 vowels = 700   Each group contains 7 letter.   Number of ways of arranging 7 letters among themselves   = 7 ! = (7 x 6 x 5 × 4 × 3 × 2 × 1) = 5040 .   So, Required number of words = (5040 × 700) = 352800 .Answer 352800
<result>B</result>
Out of 8 consonants and 5 vowels, how many words of 4 consonants and 3 vowels can be formed?