Пусть первому переводчику потребуется х дней на перевод всей книги самостоятельно, второму - у дней, а третьему z дней.
Тогда 1/x-производительность первого за 1 день
1/y-производительность второго за 1 день
1/z-производительность третьего за 1 день
1/x +1/y=1/15
1/y+1/z=1/10
1/x+1/z=1/3
(1/x+1/y)+(1/y+1/z)+(1/x+1/z)=1/15+1/10+1/3
2/x+2/y+2/z=1/2
2(1/x+1/y+1/z)=1/2 /:2
1/x+1/y+1/z=1/4
Следовательно за 1 день все трое сделают 1/4 работы.
Отсюда следует, что вся работа будет выполнена за 4 дня
1. The girl was looked for everywhere.
2. The boy wasn't listened to.
3. The patients were looked after well.
4. Our address was asked for.
5. These papers were looked throught this morning.
6. My brother will be given English lessons.
7. I have been shown an intresting magazine.
8. He was told everything by his friend.
9. The famous lecturer was warmly greeted by the students.
10. A huge plant has recently been built in the town of N.
11.The work must be finished by tomorrow.
12. When I fell ill, the doctor was sent for.
13. Helen was shown the nearest way to the theatre.
14. His patient was given some good advice.
15. I have been told the news by Mary.
16. The little boy was looked at with interest.
17. The paper was examined attentively.
3т = 3000 кг
3000 : 100 = 30 кг асфальта необходимо на 1 м²
30 × 12000 = 360000кг = 360т асфальта - необходимо