Question

A thief escaped from police custody. Since he was sprinter he could clock $40km/hr$. The police realized it after $3$ hr and started chasing him in the same direction at $50km/hr$. The distance travelled by police is equal to

• A. $20km$
• B. $600km$
• C. $660km$
• D. $360km$

Answer 1

Answer: (B)

$600km$

When the police realised that the thief escaped from custody,

Distance travelled by the thief $=40km/hr\times 3hr$

$=12km$

$[Distance=Speed\times time]$

Let the police overtake the thief after x hrs

By $x$ hrs, distance travelled by thief $=40x+120$

distance travelled by police $=50xkm$

$\therefore 40x+120=50x\Rightarrow 50x-40x=120\Rightarrow 10x=120x=\frac{120}{10}=12$

$\therefore$ Distance travelled by police =$50x=50\times 12km=600km$