ahemmm how many tiles or rectangles in the grid? well, notice, each quadrant is a 9x11 rectangles, so there are 9*11 rectangles in each quadrant, there are 4 quadrants, thus 4 * 9 * 11 rectangles in the grid.
where's the y-intercept? well, just look at the line, what are coordinates where the graph touches or intercepts the y-axis? well, is at (0,3).