question_answer

Kunal walks 10 km towards North. From there, he walks 6 km towards South. Then, he walks 3 km towards East. How far and in which direction is he with reference to his starting point?

A)  5 km West                   

B)  5 km North-East

C)  7 km East                    

D)  7 km Wast

Correct Answer: B

Solution :

The movements of Kunal are as shown in adjacent figure. (A to B, B to C and C to D). \[AC=(AB-BC)=(10-6)km=4\,\,km\] Clearly, D is to the North-east of A. \[\therefore \] Kunal's distance from starting point A             \[=AD=\sqrt{A{{C}^{2}}+C{{D}^{2}}}\]             \[=\sqrt{{{4}^{2}}+{{3}^{2}}}=\sqrt{25}=5\,\,km\] So, Kunal is 5 km to the North-east, of his starting point.