Bricklayer Brenda would take 9 hours to build a chimney alone, and bricklayer Brandon would take 10 hours to build it alone. When they work together they talk a lot, and their combined output is decreased by 10 bricks per hour. Working together, they build the chimney in 5 hours. How many bricks are in the chimney?
<spanclass=′latex−bold′>(A)</span>500<spanclass=′latex−bold′>(B)</span>900<spanclass=′latex−bold′>(C)</span>950<spanclass=′latex−bold′>(D)</span>1000<spanclass=′latex−bold′>(E)</span>1900