Two trains leave the station at the same time, one heading west and the other east. the westbound train travels 12 miles per hour slower than the eastbound train. if the two trains are 680 miles apart after 4 hours, what is the rate of the westbound train?

Rick is driving to his uncles house in greenville,which is 120 miles from ricks town .after covering x miles rick she's a sign stating that greensville is 20 miles away. which equation when solved will give the value of x. a: x+120 = 20 b: x x120 =20 c: x +20 equals 120 d: x x20= 120