Your brother and sister took turns driving on a 580 mile trip that took 10 hours to complete. your brother drove at a constant speed of 55 miles per hour and your sister drove at a constant speed of 60 miles per hour. how long did each person drive.
let the time the boy drove be x and that the girl drove be y: x+y=10 thus x=10-y........i
distance=speed*time the distance each one drove will be: 55x+60y=580....ii substituting i in ii we get: 55(10-y)+60y=580 550-55y+60y=580 5y=30 y=6 hours thus x=10-6=4 hours hence the boy drove for 4 hours and the girl for 4 hours
