classic math question........

ok, so if you are driving home from lexington..say....at about 47 mph...and can see lightening, hear thunder and see rain in the rearview mirror.......seemingly heading in the same direction as your house........how fast is the storm traveling....and can you beat the rain home and grab the cushions off the back deck before the deluge?..........the answer appeared to be 1) the storm is traveling 46.85 mph......and yes, i could grab the cushions if i threw down my purchases just inside the door and bolted for the backdoor toward the deck.......wow.......home just in time.......of course....cayle has a poolparty/sleepover scheduled to start at 5:30 pm......so this rain/thunder/lightening is most unwelcome..........