a pool contractor manages three separate teams to design and build a pool. and engineer draws that plans and obtains the permit; a construction team digs the pool, pours concrete, and finishes the pool; and an equipment contractor installs the filtration and cleaning systems. the design phase is priced at $4000, the construction phase at $20000, and the equipment phase at $9000. each phase takes on month to complete and is considered a separate performance obligation. a hotel contracts on August 1 to build a pool, pays $10000 on August 1, pays $20000 on October1, and pays the balance upon completion on October 31. How much revenue should the pool contractor recognize for the month of October?