Предмет: Математика, автор: Mrs1X

1.Из пункта А и В одновременно навстречу друг другу вышли плот и катер. Катер встретил плот через 6ч после выхода, а еще через 40мин прибыл в пункт В.Сколько времени плыл плот из В в А?
2.собственная скорость лодки вчетверо больше скорости течения реки. Найдите собственную скорость лодки и скорость лодки по течению, если, двигаясь против течения, она прошла 10,8км за 1,5ч .
(С решением )

artalex74: здесь 2 самостоятельные задачи. разбивай их на 2 разных вопроса и у тебя появится хотя бы шанс, что кто-то возьмется их решить

Ответы

Автор ответа: tanyacool

1) катер плыл 6ч до встречи и 6 2/3ч всего
х-скор катера
за 6ч он прошёл 6х, всего 6 2/3х
2/3х прошёл плот до встречи за 6ч
2/3х:6=х/9 скор плота, то есть скорость плота в 9раз меньше скорости катера, значит времени ему надо в 9раз больше
6 2/3*9=60ч плыл плот
2) х-скор теч
4х- собств скор лодки
10,8:1,5=7,2 км/ч скор против теч
4х-х=7,2
3х=7,2
х=2,4км/ч скор течения
7,2+2,4=9,6км/ч собств скор лодки
9,6+2,412км/ч скор лодки по течению

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