NIMCET 2017 — Reasoning PYQ

A is the starting point and B is the ending point.  
AD = 16 km, FB = 20 km  

EH = DF = 8 km,  
BD = FB - DF  
BD = 20 - 8 km  
BD = 12 km  

By Pythagoras theorem,  
$B{A}^2=A{D}^2+B{D}^2$  
$B{A}^2=16^2+12^2$  
$B{A}^2=256+144$  
$B{A}^2=400$  
$BA=\sqrt{400}$  
$BA=20\text{ km}$  

Raghav is 20 km in North-West direction with respect to his home.  
Hence, '20 km North-West' is the correct answer.