Place the alphabets E,F,O,R in a box
The variations of E,F,O,R can be,
E,F,O,RE,R,O,FO,R,E,FO,F,E,R
Total =4
When the box starts from 1st place then the total words will be
=4×2!×3!=48
Same thing is repeated till 6th place
Hence the total number of words
=6×48=288