A man travelled 30 km east of a place A and B he. From B he travelled 60 km west of B and  reached C. find the distance of a and c 

As, the man travels 30 km east of the place A to reach B  and then travels 60 km west of B to reach C.
When the man reaches B, the place A lies to the west of B. So, the man when travelling towards place C from B first reaches A  after travelling 30 km.
Now from A he travels 30 km more to reach C as he travels a total of 60 km towards west from B.
​Hence, the distance between A and C is 30 km.