Let the number of hours worked by B be x.
The hours worked by A = (12 - x)
The manhours of work finished by A = (12 - x - 2) x 0.6 + 2
(12 - x - 2) x 0.6 + 2 = x
x = 5
The total manhours o f work done by them in a day = 2*x = 2 x 5 = 10
Thus, the number of days required to finsih the work = 120/10 =12 days
Hence, option 2.