From two points A and B, the distance between which is 10 km. at the same time a cyclist and a passenger

From two points A and B, the distance between which is 10 km. at the same time a cyclist and a passenger car drove out in opposite directions. After 2/5 hours, the distance between them became 40 km. Find the speed of a car if it is known to be 4 times the speed of a cyclist

Let’s take the speed of the cyclist for x, then the speed of the car will be equal to: 4 * x.

Since they were moving in different directions, the removal speed will be equal to the sum of their speeds:

x + 4 * x = 5 * x.

We get the equation:

2/5 * (x * 5) = 40

x = 40 * 2 = 80

Then the cyclist’s speed is:

80: 4 = 20 km / h.