B. 20 m
Feedback Here, greatest have to cover a distance of ( 500-140) = 360 m to reach the winning point while B 500 m Now,
A covers 3m while B covers 4 m
A covers 360 m while B covers 4/3 x 360 = 480 m
Hence, B will be ( 500- 480) = 20 m behind the winning post.
A wins by 20 min.