Bearing in mind that

I can make this much from that, check the picture below.
So u just do 27*0.45 to get 12.15 and subtract that to get 14.85
1. 7
2. 10
3. 31
4. 5
5. -1
6. 15
7. 11
8. 29
9. -3
10. 8
11. -5
12. 13
13. 31
14. 0
15. 11
16. 6
17. 20
18. -1
19. 25
20. 12
21. 0
Answer:
I believe a is One of them