Предмет: Математика, автор: VikaMakyshina

Сплав меди и олова весит 10 кг и содержит 20% олова.Сколько меди надо добавить к этому сплаву, чтобы содержание олова уменьшилось до 10%

Ответы

Автор ответа: доминатор

20%=20/100=1/5
10*1/5=2 кг олова в сплаве
10-2=8 кг - меди в сплаве
10%=10/100 = 1/10
2:1/10=20 кг - вес нового сплава
20-2=18 кг - меди будет в новом сплаве
18-8=10 кг -
меди надо добавить к этому сплаву, чтобы содержание олова уменьшилось до 10%

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