A and B are two alloys of argentum and brass prepared by mixing metals in the proportions 7 : 2 and 7 : 11, respectively. If equal quantities of the two alloys are melted to form a third alloy C, the proportion of argentum and brass in C will be:
1
4 : 3
2
5 : 7
3
7 : 5
4
3 : 4