Question

Из одного города в противоположных направлениях вышли 2 пешехода.Один из них вышел через 2,5 часа раньше и шел со скоростью 8 км/ч. Скорость второго составляла 75% скорости первого.Через сколько часов после движения второго пешехода расстояние между ними составляло 41 км

Answer 1

1) найдем расстояние через 2,5 часа
2,5*8=20км
2) найдем расстояние, которое им предстоит пройти после выхода второго пешехода
41-20=21км
3)найдем скорость второго пешехода 
0,75*8=6км/ч
4)найдем суммарную скорость двух пешеходов
6+8=14 км/ч
5) найдем время через которое всё будет айяйяй...
21/14=1,5 часа

или в одну строку (41-2,5*8)/(8*(1+0,75))=1,5

Answer 2

Problem Analysis

We have two pedestrians who start walking from the same city in opposite directions. One of them starts 2.5 hours earlier and walks at a speed of 8 km/h. The other pedestrian walks at a speed that is 75% of the speed of the first pedestrian. We need to determine how many hours after the second pedestrian starts walking the distance between them will be 41 km.

Solution

Let's assume that the second pedestrian walks for x hours after starting. We can calculate the distance covered by each pedestrian using the formula: distance = speed * time.

The distance covered by the first pedestrian is given by: distance1 = 8 km/h * (x + 2.5) hours.

The distance covered by the second pedestrian is given by: distance2 = (0.75 * 8 km/h) * x hours.

We know that the distance between them is 41 km. Therefore, we can set up the equation: distance1 + distance2 = 41 km.

Substituting the values, we get: 8 km/h * (x + 2.5) hours + (0.75 * 8 km/h) * x hours = 41 km.

Simplifying the equation, we get: 8x + 20 + 6x = 41.

Combining like terms, we get: 14x + 20 = 41.

Subtracting 20 from both sides, we get: 14x = 21.

Dividing both sides by 14, we get: x = 1.5.

Therefore, the second pedestrian walks for 1.5 hours after starting.

Answer

The distance between the two pedestrians will be 41 km after the second pedestrian walks for 1.5 hours.