Question

Машинист провел поезд за 7 ч 30 мин вместо 9 ч по графику. На сколько процентов было увеличено среднюю скорость?Буду благодарна за ответы ! :-*

Answer 1

Пусть х км/ч - скорость по расписанию
тогда 9х км - расстояние
9х / 7,5  =  1,2х ( км/ч ) - увеличенная скорость
1,2х  - х = 0,2х (км/ч) - на столько увеличилась скорость
х км/ч - 100%
0,2х км/ч - ?%
0,2х * 100 : х=20%
ответ: скорость увеличилась на 20%

Answer 2

7,5+7,5x/100=9
7,5x/100=1,5
7,5x=150
x=20
ответ: на 20%

Answer 3

Calculation of Increased Average Speed

To calculate the percentage increase in average speed, we need to compare the scheduled time with the actual time taken by the train.

The scheduled time for the train journey was 9 hours, but the train actually took 7 hours and 30 minutes.

To find the percentage increase, we can use the following formula:

Percentage Increase = ((Actual Time - Scheduled Time) / Scheduled Time) * 100

Let's calculate the percentage increase in average speed using this formula.

Calculation:

Scheduled Time = 9 hours Actual Time = 7 hours and 30 minutes

Converting 7 hours and 30 minutes to hours: 30 minutes = 30/60 = 0.5 hours

Actual Time = 7 hours + 0.5 hours = 7.5 hours

Percentage Increase = ((7.5 hours - 9 hours) / 9 hours) * 100

Calculating the percentage increase:

((7.5 - 9) / 9) * 100 = (-1.5 / 9) * 100 = -16.67%

Therefore, the average speed was decreased by approximately 16.67%.

Please note that the negative sign indicates a decrease in average speed.

I hope this helps! Let me know if you have any further questions.