In how many different ways can the letters of the word 'OPTICAL' be arranged so that the vowels always come together?
Choose the correct answer
A) 120  B) 720  C) 4320  D) 2160  E) 3570
The word 'OPTICAL' contains 7 different letters.   when the vowels OIA are always together, they can be supposed to form one letter.   Then, we have to arrange the letters PTCL (OIA)   Now, 5 letters can be arranged among themselves in 3!=6 ways.   Required number of ways =(120*6)= 
<gadget id="calculator">(120*6)</gadget>
<output>720</output>
720.   Answer is 720
<result>B</result>
In how many different ways can the letters of the word 'OPTICAL' be arranged so that the vowels always come together?