two boats facing each other from opposite sides of a river both leave at the same time heading toward each other. Although one boat is traveling at a faster rate than the other, both of their rate are consistent. the first time the boats meet, they are 700 yards from one shore.they pass each other and continue on to the other side of the river, then turn around (with no time loss) and head back toward each other, continuing at their same rates. the second time they meet, they are now 300 yards from the other shore. assuming there is no current, what is the width of the river.
please explain your answer