A can finish a work in 60 days. He works at it for 15 days and then B alone finishes the remaining work in 48 days. In how much time can A and B working together finish the work?

A can finish the entire work in 60 days.

A works for 15 days.

B alone finishes the remaining work in 48 days.

Work done formula:

​$$\text{Efficiency} = \frac{\text{Total Work}}{\text{Total time to complete work}}$$ 

​$$\implies \text{Total Work} = \text{Efficiency}\times {\text{Total time to complete work}}$$​​

Combined work rate of two workers is the sum of their individual work rates.

Let efficiency of A be A and efficiency of B be B. 

Then,

Thus, the time taken by A + B to complete the work is $$\frac{960}{31}days$$​​