A thief steals a car at 1.30 p.m. and drives it off at 40 km/hr. The theft is discovered at 2 p.m. and the owner sets off in another car at 50 km/hr. He will, overtake the thief at

by the time theft is discovered theif has already travel for 30 min

i.e, distance = speed*time

distance covered by theif by 2 pm = 40*$$\frac{1}{2}$$ = 20 km

diffrence b/w the speed of owner and theif = 50-40 = 10 kmph

that means every hour after 2 pm the owner will cut the distance short b/w theif and himself by 10 km

so as theif is 20 km far from owner he will take 2 hrs to catch the theif

therefore time to overtake the theif = 2+2 = 4 pm