Mithila starts her journey from point D and walks 10 m to reach point E. She…
Mithila starts her journey from point D and walks 10 m to reach point E. She then takes a turn and walks 6 m to reach point F. She takes another turn and walks 8 m to reach point G. She takes one more turn and walks 4 m to reach point H. The diagrams below show the two possible arrangements of these points, depending on the direction of each turn.
If point H is in the East direction with respect to point G, then in which direction did Mithila start her journey (that is, from D to E)?
Answer: C. North — Concept: When a walking path is described only by turns (without stating whether each turn is left or right), two mirror-image layouts of the points are…
- A.
East
- B.
West
- C.
North
- D.
South
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Correct answer: C
Concept: When a walking path is described only by turns (without stating whether each turn is left or right), two mirror-image layouts of the points are possible. One extra directional fact about a pair of points is enough to tell the two layouts apart; once the correct layout is identified, any direction along it is read off directly — upward is North, downward is South, rightward is East, leftward is West.
Compare the two diagrams: in the upper diagram, H lies to the West of G; in the lower diagram, H lies to the East of G.
The question states that H is to the East of G, so the lower diagram is the one that applies; the upper diagram is discarded.
In the lower diagram, the D–E segment is a vertical line with D lying below E, so travelling from D to E means moving from the lower point straight up to the higher point.
A move straight up from a lower point to a higher point is the North direction.
Cross-check: trace the whole path on the lower diagram — D to E (North) → E to F (East, since F lies to the right of E) → F to G (South, since G lies below F) → G to H (East, since H lies to the right of G). This last leg reproduces exactly the condition given in the question (H East of G), confirming the lower diagram, and hence North, is the correct choice.
Mithila therefore started her journey, from D to E, in the North direction.