After the huge snow storm, i spent my snow day shoveling my driveway because our snow blower died. after shoveling for 20 minutes i had cleared all but 50 feet of the driveway. after 1 hour i only had 10 feet yet to be cleared. assume that thr number of the feet left to be shoveled varies linearly the number of minutes since i began graph the situation using a suitable domain wnd label all parts of the graph