Two workers ‘A’ and ‘B’ working together completed a job in 5 days. Had ‘A’ worked twice as efficiently as he actually did and ‘B’ worked one-third as efficiently as he actually did, the work would have completed in 3 days. In how many days could ‘A’ alone complete the job?

• A. \(3\frac{1}{2}\:days\)
• B. \(4\frac{1}{6}\:days\)
• C. \(5\frac{1}{2}\:days\)
• D. \(6\frac{1}{4}\:days\)