Предмет: Математика, автор: sashaloginova

помогите решить задачу по действиям
За первый день скошенная трава потеряла 10 процентов влаги, а за второй 5 процентов , после чего осталось 171 тонна травы.Сколько тонн травы было


полюся1518: 10+5=15%
полюся1518: 100-15=75%
полюся1518: 171 т=75%
полюся1518: 75%=75:100=0.75
полюся1518: 171:0.75=22.8 тонн- было
полюся1518: ой, 228 тонн
полюся1518: правильно?
sashaloginova: а пояснения

Ответы

Автор ответа: BORBOS17
2
1) 100% - a т
90% - x т
x=90a/100=9a/10 т
2) 100% - 9a/10 т
95% - x т
x=95*9a/100*10=0.855a т
0.855a=171
a=200 т
Ответ: 200 т
Автор ответа: доминатор
4
было 100%
100-10=90% - стало после первого дня
90/100*5=4,5 % потеряла влаги трава за 2й день
90-4,5=85,5% - составляет 171 т
171/85,5*100=200 т - травы было
Похожие вопросы
Предмет: Английский язык, автор: Fakers3d
1. Put in articles where necessary.
1. This is … pencil. … pencil is red.
2. … squirrel eats nuts.
3. … moon moves round the earth.
4. Mr Brown is … driver.
5. I haven’t got … dog, I’ve got … cat.
6. It’s … film Carmen advised me to see.
7. We often spend our holidays in … country.
8. There is … book on … desk.
9. Close … window, please! It’s extremely cold!
10. My mum is in … garden.
2. Put the verbs into Present Perfect, Past Perfect and Future Perfect.
to arrive
1. Our taxi … by 9 o’clock yesterday morning.
2. Let’s go. The guests already … .
3. They … by the time the meeting starts.
to be
4. I am tired of waiting. Where you … ?
5. By the time I’m 30 I … a famous scientist.
6. He didn’t remember where he … before the accident.
to paint
7. We … the house by next Tuesday.
8. She … more than 10 pictures already.
9. I wondered if they … the room.

3. Choose the correct word.
1. She will have finished her resume … (on Monday/by Monday/last Monday).
2. The aircraft hasn’t landed … (yet/just/already).
3. We have lived in New York … (since/from/for) three years.
4. … (After/Already/Ago) they had eaten the cake, they cleared the table.
5. They will have decorated the Christmas tree … (by the time/before/by then).
6. My uncle has … (already/yet/ago) repaired his car.
7. I haven’t met them … (from/since/for) their wedding.
8. … (By the time/Already/Just) the sun set, the farmers had already stopped working.
9. Have you … (just/ever/yet) been married, Kelly?
10. … (When/How much/How long) has he known her?

Предмет: Русский язык, автор: Elick0007