Предмет: Математика, автор: NataliyaSt

три бригады строителей должны построить 2 одинаковых дома.на строительство одного дома первой бригаде потребуется 9 недель,второй бригаде-в 1.1/3 раза больше времени,а третьей бригаде-в 2 раза больше времени,чем  первой.,за сколько недель три бригады построят 2 дома,работая совместно?

Ответы

Автор ответа: jekadva
0
1)9*1 1/3=9*4/3=12 недель построит вторая бригада
2)9*2=18 недель построит третья бригада
3)1/9дома -первая бригада за 1 неделю
4)1/12 дома-вторая бригада за 1 неделю
5)1/18 дома-третья бригада за 1 неделю
6)1/9+1/12+1/18=9/36=1/4 дома за 1 неделю построят  бригады вместе
7)2:1/4=за 8 недель три бригады построят два дома работая совместно.
Ответ:за 8 недель.

Похожие вопросы
Предмет: Английский язык, автор: EsQ04
1. His eyes … hazel.
a) am, b) is, c) are.
2. I and my friends … interested in basketball.
a) am, b) is, c) are.
3. David drives his car … work.
a) at, b) with, c) to, d) in, e) of
4. Richard plays football … his classmates at school.
a) at, b) with, c) to, d) in, e) of
5. After, do, go, school, you, where?
a) Do you where go school after?
b) Where do you go after school?
c) Do where you go school after?
d) Do after school you where go?
6. Time, up, she, what, does, get?
a) What time does she get up?
b) Does she what time get up?
c) What does she time get up?
d) What time does get up she?
7. Robert and William tidy … room every day.
a) my, b) his, c) her, d) our, e) their.
8. What days of the week do you have English?
a) Monday, b) Tuesday, c) Wednesday, d) Thursday, e) Friday.
9. Find the antonym: selfish
a) generous, b) rude, c) kind, d) lazy, e) polite
10. Find the synonym: funny
a) envious, b) curious, c) gifted, d) nice, e) amusing
11. Translate the word: helpful
a) отзывчивый, жауапты.
b) упрямый,бірбеткей
c) добрый, мейірімді
d) жизнерадостный, көңілді
e) спокойный, сабырлы
12. Diana … a little dog.
a) has got, b) have got, c) am, d) is, e) are
13. I … a big family.
a) has got, b) have got, c) am, d) is, e) are
14. Gina helps people withdraw and deposit money into their bank account. She is a…
a) Account
b) Cashier
c) Bank teller
15. David helps people pay for their groceries in a supermarket. He is a…
a) Cashier
b) Shop assistant
c) Shop manager
16. Rita helps sick animals. She is a ...
a) Vet
b) Nurse
c) Doctor
17. There was a terrible __________ in the Alps last week. Several skiers are in still hospital.
a) avalanche
b) earthquake
c) hurricane
18. Which is an example of climate change?
a) deforestation
b) air pollution
c) global warming
19. _______ are rain drops that have formed together into ice.
a) hailstorms
b) earthquake
c) landslide
20. Which of these natural phenomena is a land movement disaster?
a) floods
b) droughts
c) earthquakes
21. Which of these natural phenomena is a water disaster?
a) tsunamis
b) blizzards
c) tornadoes
22. There hasn’t been a(n) __________ from this volcano for 50 years at least.
a) avalanche
b) ash
c) eruption
23. Such acts of nature are called natural _______.
a) disasters
b) earthquakes
c) tornadoes
24. In Costa Rica the volcano Irazu _______ in 1963, destroying farms and spreading ash over San Jose.
a) Caused,
b) injured
c) erupted
25. No part of the world is totally free from _______ disasters.
a) earthquakes
b) natural
c) damage
Предмет: Математика, автор: zhanelzhukina