Correct option is (c) 10\(\frac 14\) days
Portion of work done by A and B in first two days = \(\frac 19 + \frac 1{12}\)
\( = \frac {4 + 3}{36} \)
\(= \frac 7{36}\)
Portion of work done in the first 10 days = \(\frac {35}{36}\)
Remaining work = \(1 -\frac{35}{36}\)
\(= \frac{36-35}{36}\)
\(= \frac 1{36}\)
Therefore, time taken by
\(A = \frac 1 {36} \times 9 = \frac 14 \) day
Hence, total time = \(10 + \frac 14\)
\(= \frac{40 + 1}4\)
\(= \frac{41}4\)
\(= 10\frac14\) days
