Question

Из двух городов, расстояние между которыми 90 км,одновременно навстречу друг другу выехали велосипедисты.Первый ехал со скоростью 20 км/час,а второй - 10 км/час.Через сколько времени они встретятся?Варианты 1)2часа 2)10 часов 3)3 часа 4)5 часов

Answer 1

Вариант: 3) 3 часа
Рада помочь

Answer 2

1)20+10=30(км)- общая скорость.
2)90:30=3(ч)
Ответ: Через 3 часа они встретятся . 

Answer 3

Problem Analysis

We have two cyclists traveling towards each other from two different cities. The distance between the cities is 90 km. The first cyclist is traveling at a speed of 20 km/h, while the second cyclist is traveling at a speed of 10 km/h. We need to determine how long it will take for them to meet.

Solution

To find the time it takes for the two cyclists to meet, we can use the formula:

Time = Distance / Relative Speed

The relative speed is the sum of the speeds of the two cyclists since they are traveling towards each other.

Let's calculate the time it takes for them to meet:

Distance = 90 km

Relative Speed = 20 km/h + 10 km/h = 30 km/h

Time = 90 km / 30 km/h = 3 hours

Therefore, the correct answer is 3 hours (Option 3).

Conclusion

The two cyclists will meet after 3 hours of traveling towards each other.