One inlet pipe can fill an empty pool in 16 hours, and drain an empty the pool in 20 hours. how long will it take the pipe to fill the pool if the drain is left open?

Item 1 use the polygon tool to draw a rectangle with a length of 4 units and a height of 2 units. one of the sides of the rectangle falls on line ef , and the rectangle has a vertex of e. each segment on the grid represents 1 unit.