ay from the book, but I need step by step solution

Environmental Engineering, fundamentals, sustainability, design, ed.2, Question 7.6A small public well is used to supply drinking water to a small residential community located in a 26 square-kilometer watershed. For the month of June, the measured rainfall was 12 cm, the estimated evapotransiration was 7.5 cm and the surface water runoff entered a small stream with an average flow of 0.32 m/sec that leaves the watershed. Estimate the average flow (m/day) from the public well without depleting the underlying aquifer (neither gains nor loses water). Assume that all water that infiltrates will percolate to the aquifer.The answer is Q= 11,350 m3/day from the book, but I need step by step solution