Question

поезд должен пройти 700 км за 9 часов .Первые 3 часа он шёл со скоростью 70 км/ч,следующие 2 часа-со скоростью 85 км/ч. С какой скоростью он должен идти оставшийся путь ,чтобы прийти в пункт назначенния по расписанию?

Answer 1

3*70=210 км первые три часа
85*2=170 км два часа
210+170=380 км прошел за пять часов
700-380=320 км осталось пройти
9-5=4 часа
320:4=80 км/ч должна быть скорость

Answer 2

Problem Analysis

We are given that a train needs to travel a total distance of 700 km in 9 hours. The train traveled at a speed of 70 km/h for the first 3 hours and at a speed of 85 km/h for the next 2 hours. We need to find the speed at which the train should travel for the remaining distance in order to arrive at its destination on schedule.

Solution

To find the speed at which the train should travel for the remaining distance, we can use the formula:

Speed = Distance / Time

Let's calculate the distance covered in the first 3 hours and the next 2 hours:

Distance covered in the first 3 hours = 70 km/h * 3 h = 210 km Distance covered in the next 2 hours = 85 km/h * 2 h = 170 km

The total distance covered in the first 5 hours is 210 km + 170 km = 380 km.

To find the remaining distance, we subtract the total distance covered in the first 5 hours from the total distance of 700 km:

Remaining distance = 700 km - 380 km = 320 km

Now, we can calculate the speed at which the train should travel for the remaining distance:

Speed = Remaining distance / Remaining time

The remaining time is 9 hours - 5 hours = 4 hours.

Speed = 320 km / 4 h = 80 km/h

Therefore, the train should travel at a speed of 80 km/h for the remaining distance in order to arrive at its destination on schedule.

Answer

The train should travel at a speed of 80 km/h for the remaining distance in order to arrive at its destination on schedule.