Question

two runners moving at a constant velocities are at opposite ends of a straight 200m track that runs north-south. runner A starts out from the south end at 4.0m/s North. Runner B starts from the north end at an unknown velocity south. if both runners meet in 18s, then what is the velocity of Runner B?

Answer 1

let velocity be x,
v1 t1 + v2 t1 = total distance
v1 is 4 m/s and total distance is 200m
if you can do simple mathematics, you should be able to do this.