question_answer

A traveller starts from a point A and travels 3 km eastwards to B and then turns left and travels thrice that distance to reach C. He again turns left and travels five times the distance he covered between A and B and reaches his destination D. The shortest distance between A and D is

A)  12 km                         

B)  15 km          

C)  16 km                         

D)  18 km

Correct Answer: B

Solution :

 : The movements of the traveller are as shown in the adjoining diagram.                               DE=15-3=12km, AE = BC = 9 km Use Pythagoras theorem in AADE to determine AD.