The number of six letter words that can be formed using the letters of the word "ASSIST" in which S's alternate with other letters is

The correct option is A

12

All S's can be placed either at even places or at odd places, i.e, in 2 ways.

The remaining letters can be placed at the remaining places in 3!, i.e. in 6 ways.

$\therefore$ Total number of ways =$6\times 2=12$