How many arrangements of the letters of the word REMAND is possible if they have REM together in any order?
The answer shows $^3P_ 3 \times \, ^4P_4 = 144$
I get that the $^3P_3$ part because there are $6$ possible ways to arrange REM, however, why should the second part of the answer be $^4P_4$, shouldn't it be $^3P_3$ since only three letters are left to be arranged?
Thank you!