The ratio of copper and zinc in alloy A is 5 : 7 and that in alloy B is 4 : 5. A and B are taken in the ratio of 1 : 2 and mixed to form a new alloy C. What part of C is copper?
1
\(\frac{47}{108}\)
2
\(\frac{5}{12}\)
3
\(\frac{4}{9}\)
4
\(\frac{61}{108}\)