Question

Использование нового трактора для вспашки дало экономию времени в 70% и заняло 42 ч. Сколько времени потребовалось бы для выполнения этой работы на старом тракторе?

Answer 1

по условию задачи новый трактор за 30% времени выполнил работу за которую старый трактор тратить 100% времени и это составило 42 часа

 составим пропорцию:   30%-42ч

                                   100%-Хч.  тогда 30Х=4200

                                                              Х=4200:30

                                                              Х=140 часов

 ОТВЕТ: 140 часов потребуется для выполнения работы на старом тракторе

Answer 2

72%-42ч.

100%-?

составляем уравнение

42*100=72х

4200=72х

х=60ч.

Answer 3

Calculation of Time Saved Using the New Tractor

To calculate the time saved using the new tractor for plowing, we need to know the percentage of time saved and the time it took to complete the task with the new tractor.

According to the information provided, using the new tractor for plowing resulted in a time savings of 70% and took 42 hours to complete the task.

Calculation

To find out how much time would be required to complete the same task with the old tractor, we can use the following formula:

Time with old tractor = Time with new tractor / (1 - Percentage time saved)

Plugging in the values:

Time with old tractor = 42 hours / (1 - 0.70)

Calculating:

Time with old tractor = 42 hours / 0.30

Time with old tractor = 140 hours

Therefore, it would take approximately 140 hours to complete the plowing task using the old tractor.

Please note that the calculation assumes that the efficiency of the old tractor remains constant and that the conditions and circumstances of the task are the same for both tractors.