Предмет: Математика, автор: fyzreyw1

Первый насос наполняет бак за 1 час, второй — за 1 час 30 минут, а третий — за 1 час 48 минут. За сколько минут наполнят бак три насоса, работая одновременно

Ответы

Автор ответа: renatas82
2
1 насос-1 час
2 насос-1 час 30 мин. =3/2 часа
3 насос- 1 час 48 мин=9/5 часа
производительность общая
1/1+1/(3/2)+1/(9/5)=1+2/3+5/9=(9+6+5)/9=20/9
время 1/(20/9)=9/20часа=9*60/20=27 мин
ответ 27 мин
Автор ответа: vladlevshin06
0

Ответ:27 мин

Пошаговое объяснение:1 насос-1 час

2 насос-1 час 30 мин. =3/2 часа

3 насос- 1 час 48 мин=9/5 часа

производительность общая

1/1+1/(3/2)+1/(9/5)=1+2/3+5/9=(9+6+5)/9=20/9

время 1/(20/9)=9/20часа=9*60/20=27 мин

ответ 27 мин

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Помогите перевести, только никак в переводчике, где предложения некоторые не связанные по смыслу и грамматически. А чтоб был понятный текст.

Буду очень благодарна.

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10 July was a very special day. In fact, it was Jack Petersons birthday. On that day everybody tried to do something nice for him. Mum and Dad always gave him a lot of presents and took him a lot of presents and took him to interesting places. Two years ago they went on an excursion to Mars. Last year they went to the Galaxy Zoo. They saw interesting animals there: bats, rabbits, hens and the most exciting thing: a real dog!

Yes, all Jack`s birthday were great, but this year – 2170 – his Grandfather promised him the best present. «On your birthdayGranddad saidwe`ll go camping

«Camping?» Jack didn`t know this word, so he wasn`t really interested, but suddenly he heard him mum`s voice.

«Camping!» she cried. «What are you talking about?» «You can`t put the life of my child in danger!» «It`ll be OK, Kate,» Grandfather sighed. «We`ll wear our masks and we`ll take a lot of extra oxygen with us.» «And you won`t touch anything! Do you promise, Dad?» Jack`s mum shouted. «Of course I promise,» Granddad answered. After this conversation Jack really wanted to go camping. «Camping is dangerous – it`s a real adventure,» he thought.

On the morning of 10 July Dranddad woke Jack up very early. They put their masks on and went outside. It was dark. Jack knew about the sun, but he never saw it. They went to the forest. There were six trees and a little river. Grandfather found a stick and started digging a hole in the ground. He looked sad. «What are we going to do?» Jack asked.