Partnership accounts entry

Dear friends please help me with the following problem.

A and B start construction of a building. A holds the land and B agrees to bear all expenses to construct the building. They made agreement to share the total number of flats in 2:3 ratio that is A will sell 40% of total flats separately and B will sell 60% of flats separately. I am to keep the accounts of B only. How to set up capital and how make all accounting.