How many arrangements of four 0's (zeroes), two 1's and two 2's are there in which the first 1 occur before the first 2?
A. 420
B. 360
C. 320
D. 210
Answer: Option D
Solution(By Examveda Team)
Total number of arrangements = $$\frac{{8!}}{{4! \times 2! \times 2!}}$$ = 420 Since, there are two 1's and two 0's, the number of arrangements in which the first 1 is before the first 2 is same as the number of arrangement in which the first 2 is before the first 1 and they are each equal to half the total number of arrangements = 210Join The Discussion
Comments ( 1 )
Related Questions on Permutation and Combination
A. 3! 4! 8! 4!
B. 3! 8!
C. 4! 4!
D. 8! 4! 4!
A. 7560,60,1680
B. 7890,120,650
C. 7650,200,4444
D. None of these
A. 8 × 9!
B. 8 × 8!
C. 7 × 9!
D. 9 × 8!
Since, there are two 1's and two 2's, the number of arrangements in which the first 1 is before the first 2 is same as the number of arrangement in which the first 2 is before the first 1 and they are each equal to half the total number of arrangements = 210