A man can walks on hard ground with a speed of 5 ms−1 and on sandy ground with 3 ms−1 . Let he is standing on border of sandy and hard ground and wishes to reach the tree situated on the sandy ground as shown below.
He can reach tree in least time when he walks on hard ground upto point E and then he walks straight towards tree along EO. Distance AE is
(a) 10 m
(b) 20 m
(c) 30 m
(d) 50 m