Предмет: Математика, автор: NekoTyan03

Если одному рабочему, чтобы выполнить какую- то работу потребуется 7 с половиной часов, а другому рабочему на эту же работу нужно 5 часов, то за сколько времени они смогут выполнить ее вместе?

Ответы

Автор ответа: Hrisula

Задача решается через нахождение производительности труда, т.е. количество выполняемой работы за единицу времени.
Примем всю работу за единицу.
Тогда за один час первый рабочий выполнит 1:7,5=10/75 части работы
Второй - 1/5 работы в час.
Вместе за один час рабочие выполнят
10/75+1/5=1/3 часть работы
Всю работу они выполнят за
1:¹/₃=3 (часа)

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