In how many different ways can the letters A, A, B, B. B, C, D, E be arranged if the letter C must be to the right of the letter D?
1,680
2,160
2,520
3,240
3,360
1,680
2,160
2,520
3,240
3,360
IMO A
AABBBCDE
total arrangements: 8!/3!2!
Thus C right to D: 8!/3!2!2 (in half it will be to the left of D and in other half to the right of D)
thus 1680
