A can do a piece of work in 15 days. B is 25% more efficient than A and C is 40% more efficient than B. A and C work together for 3 days and then C leaves. A and B together will complete the remaining work in:
1
\(2\frac{1}{2}\) days
2
\(3\frac{1}{2}\) days
3
4 days
4
3 days