question_answer

Kunal walks 10 km towards North. From there he walk km towards South. Then, he walks 3 km towards East. How far and in which direction is he with reference to his starting?

A)  5 km West                   

B)  7 km West 

C)  7 km East                    

D)  5 km North-East

Correct Answer: D

Solution :

Clearly, Kunal moves from A 10 km Northwards upto B, then moves 6 km Southwards upto C, turns towards East and walks 3 km upto D. Then, \[AC=(AB-BC)=(10-6)+4\,km;\]             \[CD=3\,\,km.\] So, Kunal's distance from starting point A \[=AD=\sqrt{A{{C}^{2}}+C{{D}^{2}}}=\sqrt{{{4}^{2}}+{{3}^{2}}}=5\,\,km\] Also D is to the North-East of A.