Your answer for 21. x = 4/5, b 19. n = -2/3, a
Answer:
C
Step-by-step explanation:


Answer: 121
It would be 4.8333333333.
The three repeats here.
Number of ways the second grade students can sit on the first row is 5! = 5P5
Number of ways 15 first grade students can sit in the remaining 20 seats is 20P15
Therefore, required number of ways is 5P5 * 20P15. (option B)