RAS question
Ramesh walks 10 km North, turns left and walks 5 km, turns left again and walks 10 km, then turns right and walks 5 km. How far and in which direction is he from the starting point?
Correct answer: (A) 10 km West.
Ramesh is 10 km west of his starting point after completing the given sequence of turns and walks.
Explanation
Track the movement by facing direction after each turn, as direction-and-distance questions are solved by drawing the path from the given information. Ramesh first goes 10 km north. A left turn from north makes him face west, so he walks 5 km west. Another left turn makes him face south, and the next 10 km walk brings him back to the starting latitude. From south, a right turn again makes him face west, and he walks another 5 km west. The north-south movement cancels out: 10 km north followed by 10 km south. The only net displacement is westward, equal to 5 km plus 5 km, so his final position is 10 km west of the start.
Why the other options are wrong
- (B) 5 km west counts only one of the two westward legs and ignores the final 5 km walked after the right turn.
- (C) 10 km north treats the first leg as the final displacement, but that northward movement is cancelled by the later 10 km southward walk.
- (D) 15 km west overcounts the westward displacement; the path has only two westward legs of 5 km each, totalling 10 km.
Concept
This tests direction sense and net displacement, a recurring Reasoning and Mental Ability concept in RAS because small turn-sequence errors quickly change the answer. The key skill is to update the facing direction after each left or right turn, then cancel opposite movements.