Henry Ernest Dudeney/Puzzles and Curious Problems/276 - An Effervescent Puzzle

by : $276$

 * An Effervescent Puzzle
 * In how many ways can the letters in the word $\text {EFFERVESCES}$ be arranged in a line without two $\text E$s ever appearing together?
 * Of course, two occurrences of the same letter, such as $\text {F F}$, have no separate identity,
 * so that to interchange them will make no difference.


 * When the reader has done that, he should try the case where the letters have to be arranged differently in a circle, with no two $\text E$s together.
 * We are here, of course, only concerned with their positions on the circumference, and you must always read in a clockwise direction.