A can complete a piece of work alone in 20 days, B can do it alone in 15 days and C can complete it alone in 18 days. B and C started the work together but both were forced to leave after 4 days. The remaining work was done by A in:
1
12 days
2
\(14\frac{2}{{45}}\) days
3
\(10\frac{2}{{9}}\) days
4
\(9\frac{2}{{45}}\) days