7. Tim and a friend left a campsite on a trip down a river in a canoe maintainin

7. Tim and a friend left a campsite on a trip down a river in a canoe maintaining a constantspeed of 4 miles per hour. Four hours later Tims father set out after them in amotorboat carrying the camping supplies. The motorboat traveled at a rate of 12 milesper hour. How long after he started did Tims father overtake the boys?8. It takes a passenger train 2 hours less time than it takes a freight train to make the trip fromBrownsville to Greentown. If the passenger train averages 60 miles per hour on the trip whilethe freight train averages 40 miles per hour on the trip how far is it from Brownsville toGreentown?