In how many different way can the letters of the word "PERSONAL" be arranged so that the consonant always come together?
Solution
In " PERSONAL " there are 8 word in which vowel are A, E and O (total 3) and consonant are P,R,S,N and L(total 5) So it should be arrange as
$5! \times 4!=5\times 4\times 3\times 2\times 1\times 4\times 3\times 2\times 1$
$= 120 \times 24$
$= 2880$