The car, moving at a speed of 30 km / h, traveled half the way to the destination in 2 hours.

The car, moving at a speed of 30 km / h, traveled half the way to the destination in 2 hours. At what speed should it continue to move to reach the goal and return back in the same time?

1. The car has traveled half the way, therefore it needs to travel the same amount in order to complete the path, and twice the distance in order to return. That is, the car must travel a path three times longer than the one that it has already traveled.

2. Consider the relationship between the value of the path and the speed:

t = S / V;

Therefore, in order for the time to remain the same when the path increases by n times, it is necessary to increase the speed by the same number of times:

t = S / V = 3S / 3V;

3. Let’s increase the speed three times:

30 km / h × 3 = 90 km / h;

Answer: 90 km / h;