Question

С 2 населенных пунктов, расстояние между которыми 42 км,выехали одновременно навстречу друг другу два всадника.Первый ехал со скоростью 9 км/час,а второй -12 км/ч. Через сколько часов они встретятся?

Answer 1

9+12=21 (км/ч) - общая скорость всадников 

42:21=2 (ч.) 

Ответ: они встретятся через 2 часа

Answer 2

1) 9+12=21(км/ч)-общая скорость

 2) 42:21=2(ч)

Answer 3

Problem Analysis

We have two riders who start simultaneously from two different locations and are traveling towards each other. The first rider is traveling at a speed of 9 km/h, while the second rider is traveling at a speed of 12 km/h. We need to determine how many hours it will take for them to meet.

Solution

To solve this problem, we can use the formula: time = distance / speed.

Let's assume that the first rider starts from point A and the second rider starts from point B. The distance between the two points is given as 42 km.

The first rider's speed is 9 km/h, so the time taken by the first rider to cover the distance between the two points is: time1 = distance / speed1 = 42 km / 9 km/h.

Similarly, the second rider's speed is 12 km/h, so the time taken by the second rider to cover the distance between the two points is: time2 = distance / speed2 = 42 km / 12 km/h.

To find the total time taken for the two riders to meet, we can add the individual times: total time = time1 + time2.

Let's calculate the total time:

time1 = 42 km / 9 km/h = 4.67 hours

time2 = 42 km / 12 km/h = 3.5 hours

total time = time1 + time2 = 4.67 hours + 3.5 hours = 8.17 hours

Therefore, it will take approximately 8.17 hours for the two riders to meet.

Answer

The two riders will meet approximately after 8.17 hours.