Answer:
12/325
Step-by-step explanation:
Purple marble: 8/26 = 4/13
Blue marble after: 3/25
3/25*4/13 = 12/325
7
1) for '8'; '3'; and '10':
8/2+3+3=10
2) for '2'; '5' and '11':
2/1+5+5=11
3) for '6'; '2' and '?':
6/2+2+2=7