Предмет: Математика, автор: Аноним

От дома до школы Петя обычно едет на велосипеде со средней скоростью 300м/мин. Сегодня, выехав в то же самое время, он часть пути проехал со скоростью 240м/мин, а затем увеличил скорость до 420м/мин и приехал вовремя. Какую часть от времени, затраченного на дорогу, Петя ехал с одной скоростью, а какую часть с другой?

Ответы

Автор ответа: maffeta001

Ответ:

2/3 пути

Пошаговое объяснение:

Пусть t1- это время, которое Петя ехал со скоростью 240 м/мин

А t2-со

Tогда всё расстояние:

S=(t1+t2)*300м/мин

240t1+420t2=300t1+300t2

120t2=60t1

2t2=t1

Значит он ехал:

C v1- 1/3 пути

А с v2- 2/3 пути

Значит со скоростью t1 он ехал 2/3 пути со скоростью t2 1/3

Аноним: спс

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