9. Five marks exercise problems IV

Carpenter \(A\) takes \(15\) minutes to fit the parts of a chair while Carpenter \(B\) takes \(3\) minutes more than \(A\) to do the same work. Working together, how long will it take for them to fit the parts for \(22\) chairs?

 

Time taken to fit \(22\) chairs by \(A\) and \(B\) \(=\)  hours