A person 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 reaches his destination D. The shortest distance between the starting point and the destination is

Options

A. a. 12 km
B. b. 15 km
C. c. 16 km
D. d. 18 km

Answer

B

Explanation

The movemenrs of the person are as shown in the figure below

According to the question
`BC=(3xx3)=9` km
`CD=(3xx5)=15` km
`OD=(15-3)=12` km
Now required distance
`AD=sqrt(OD^(2)+OA^(2))`
`AD=sqrt(12^(2)+9^(2))=sqrt(144+81)=sqrt(225)` km = 15 km