Let each different arrangement of all the letters of DELETED be called a word. In how many of these words will the D's be separated? Pick
A) 150
B) 200
C) 300
D) 350
E) 400
here are 7 letters in the word "DELETED", out of which: D=2, E=3, L=1, T=1.   Total # of permutations is 7!/2!3!=420   # of permutations with D's together is 6!3!=120. Consider 2 D's as one unit: {DD}{E}{E}{E}{L}{T} - total 6 units, out of which {DD}=1, {E}=3, {L}=1, {T}=1.   # of permutations with D's not come together is: 7/2!3!−6!3!=300   ANSWER:300
<result>C</result>
Let each different arrangement of all the letters of DELETED be called a word. In how many of these words will the D's be separated?