14. The number of 11 letter words formed by using English alphabets if all vowels are used such that no two vowels are adjacent to each other is:
a. 5! * 20! / 15!
b. 5! * 21! / 15!
c. 21! / 10!
d. 21! / 15!

• Five vowels arranged alternatively in 5!ways nd in six gaps remaining 21 letters arranged in 21*20*19*18*17*16ways
  So answer is 5!*(21!/15!)
• 9 years agoHelpfull: Yes(2) No(0)
• first arrange the 5 vowels in 5!
  no of gaps to be filled to make a 11 letter word is 6. eg.. ___ A___ E ___ I ___ O ___ U__
  no of gaps is 6
  the 6 gaps can be filled in 21P6 ways (as 5 vowels are already used remaining letters are 21)
  So total no of ways= 5!* 21P6
  = 5!* (21!/15!) [that is option b]
• 7 years agoHelpfull: Yes(1) No(0)
• 5!*20! /15!
  
  
• 9 years agoHelpfull: Yes(0) No(2)