A train leaves Little Rock, Arkansas, and travels north at 70 kilometers per hour. Another train leaves at the same time and travels south at 75 kilometers per hour. How long will it take before they are 435 kilometers apart?
Train A speed= 70 km/h north Train B speed= 75 km/h south Opposite directions= add speeds 70+75=145 Distance= 435 Km Time= d/s; 435/145= 3 hours It would take 3 hours for the trains to be 435 kilometers apart