Question

ek sipahi ek chhor par khada hai tatha dosara chor dusare choor par khad hai
chor sipahi ko dekha kar 10km/h ki gati se bhagata hai tabhiu usi samaya sipahi 15km/h ki gatai se chor ka pichha karta hai sipahi chor ko kitna samaya mein pakadega

Answer 1

Speed of thief = 10 km/h 
speed of police = 15 km/h
relative speed = speed of police - speed of thief = 15-10 = 5 km/h
distance between them = 500m = 0.5 km

time taken = $\frac{distance}{relative\ speed}= \frac{0.5}{5}=0.1\ hour=0.1 \times 60=6minutes$

So the police will take 6 minutes to catch the thief.