let t be the time they both meet. when they meet they both have covered the distance between them .
arthur with 3 m/s would have covered 3t m
Betty with 2 m/s would have covered 2t m
3t + 2t = 100
5t =100
t = 100/5
t= 20 seconds
spot who is helplessly running back and forth
at 5 m/s would have done for 20 seconds.
the distance covered by spot 5 m/s * 20s = 100m
hope this helps hun
