Question

Two cars are moving in the same direction with the same
speed 30 km/hr. They are separated by a distance of 5 km,
the speed of a car moving in the opposite direction if it
meets these two cars at an interval of 4 minutes, will be
(a) 40 km/hr
(b) 45 km/hr
(c) 30 km/hr
(d) 15 km/hr​

Answer 1

Explanation:

Let the speed of that car is v km/hr

Now the relative velocity of the car with respect to that two cars is= (x+30)km/hr

Now, according to the question it meets these two cars at an interval of 4 minutes...

4min=(1/15)hrs

Now...

Time=5/(x+30)=1/15

=>x+30=75

=>x=75-30

=>x=45

Therefore the speed of the car was 45km/hr