Предмет: Математика, автор: kotemk68

решите задачу
на экзамене 30% шестиклассников получили оценку 5. сколько учеников в классе если пятерки получили 9 человек?

Ответы

Автор ответа: varlena
3
Из задачи ясно, что 9 чел получили пятерки и это 30%  
составим пропорцию
9 - 30%
Х?- 100%
Х= \frac{9*100}{30} =30 (уч)
Ответ: всего 30 учеников в классе
Предыдущий вопрос
Следующий вопрос
Похожие вопросы
Предмет: Английский язык, автор: сатана6990
Помогите с переводом , пожалуйста. Переводчики коверкают.

Alaska's history began in 1741 when it was first visited by Vitus Bering, the Danish explorer in Russian employ. At the beginning Alaska was know "Russian America". Then later it was bought by the USA from Russian in 1867 for $7.200.000. People in the US did not purchase,because they did not know wealthy Alaska was is natural resources. They called it "Seward's Folly",but since then the cost of Aiaska has been repaid many time,and William Seward,past Secretary of State,who had arranged the transaction,is known as a great statesman.
Alaska was taken into the Union as the forty-ninth state in Juiy 1958. The state in one-fifth as large as the rest of the United States. It is twice as large as Texas.
The name Alaska comes from the Aleut word "Alayeksa" that means "the great country".
In 1927 every state of America had a flag Alaska,so all the Alaska schoolchildren were as hed to take part in a contest and to submit designs for a flag. The contest was won by thrirteen-year-old Aleut boy,Benny Benson,who wrote on its back:"The blue is for the great bear, a sumbol of strength. The North Star is for the future State of Alaska, the greatest State in the Union".
Alaska is a cold, forested and largely mountainous state. Three-quartersof Alaska is in the North Temperate Zone,with temperatures like those of Scotland and Sweden.Near the town of Fairbanks it may be as cold as 66 below zero in winter, and as hot as 100 summer.
Alaska in made up of much more than ice and polar bears, oreven minerals, furs and fish. Since 1900 pioneers of every trade and profession have been coming in. Alaska has built up rapidly. The building of the Alaska Higway across Canada in 1942 has increased Alaska's commercial importance as a gateway to the Orient.
2 года назад
Предмет: Русский язык, автор: Mama1o
Помогите с 52 заданием
2 года назад
Предмет: Русский язык, автор: drinkingchild
Составьте предложения со словами- знамя, пламя, время, имя, племя, стремя, семя в родительном падеже + синтаксический разбор одного предложения.
2 года назад
Предмет: Математика, автор: marouy
Решите уравнение Пожайлуста:
:)
0,5(8х+1)=1,5-(2-4х)
8 лет назад
Предмет: Психология, автор: lilpeep1792
как не стесняться заводить друзей в реальной жизни?
​
8 лет назад