math
posted by treena on .
A northbound train and a southbound train meet each other on parallel tracks heading in opposite directions. The northbound train travels 12 miles per hour faster than the southbound train. After 2.5 hours, they are 330 miles apart. At what speeds are the two trains traveling?

distance = speed * time
2.5(x+x+12) = 330
2x+12 = 132
2x=120
x=60
so, southbound speed is 60, northbound is 72
after 2.5 hours, the trains have traveled 150 and 180 miles, respectively.