Q. The number of ways in which 9 persons can be divided into three equal groups is
A) 1680
B) 840
C) 560
D) 280
Explanation
(a)
Since each group has 3 persons hence, required number of ways$= \frac{9!}{(3!)^{3}} = \frac{362880}{6 \times 6 \times 6} = 1680$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.