There are two teams of laborers I and II at a bridge construction site. There are w workers in each team. On a particular day, a worker is transferred from Team I to Team
II. Now, if the ratio of the amount of work done by Team I in (w + 1) h (hours) and by Team II in (w +  2) h (hours) is 10 : 12 respectively, then the value of w is equal to Is ?