A robber is in a fast car, hurrying away from the scene of his crime. His car can go at 150 km/h. He will be safe if he can reach the border, 40km away. A police car arrives at the scene of the crime. The police are late! The robber has already travelled 10 km towards the border. The police car set off in hot pursuit. Question: calculate how long it will take the robber to reach the border.
Answers
A robber is in a fast car, hurrying away from the scene of his crime. His car can go at 150 km/h. He will be safe if he can reach the border, 40km away. A police car arrives at the scene of the crime. The police are late! The robber has already travelled 10 km towards the border. The police car set off in hot pursuit. Question: calculate how long it will take the robber to reach the border.
it will take about 12 mins to reach the border
Explanation:
given
the robber is in a fast car
the speed of the car is 150km/h
border is 40km away from the robber car initially
now the robber has already travelled 10km towards the border
so the remaining distrace travelled by the robber is (40-10)=30km
therefore the robber has to travel 30km more to reach the border and make himself safe
if the robber maintains the constant speed of 150km/h
in one minute distance covered by the robber with the constant speed of 150km/h is
150/60=2.5km
therefore in one minute robber can travel up to 2.5km
so to cover the remaining 30km distance ,the time taken will be
30/2.5=12min
hence the time taken by the robber to reach the border is 12minutes so that he can cover the remaining 30km with the constant speed of 150km/h
from initial point to border
it takes about 16 mins to travel 40km for the robber car by maintaining speed of 150km/h