Answer for 9th questions is option C and for 10th question is option B.
Consider the following queue
15 23 31 4 _ _
Here n=6, front points at 15(position 1) and rear points at 4(position 4) Here, front<=rear;
Option a) Numb = 6+4-1+1 = 10 False.
Option b) Numb= 10 False
Option c) Numb= 4-1+1 = 4 True
Option d) Numb = 6+4-1-1 = 8 False.
Hence Ans is c) for Q9 {credits for 9th questions answer : @Meet2698. }
Subsequently for Q10
For condition front<= rear : 9-3+1 = 7
And for condition rear<front : 12-+4-9+1 = 8
So answer option B.