Детская задача

[ymarkov]

A farmer has a vat of 3%-fat milk and a vat of 27%-fat cream. How much of each should he use to mix 30 gallons of 4%-fat milk? Is there more than one way to solve this? (Mine looks clunky to me.)

У фермера есть молоко 3% жирности и сливки 27% жирности. Сколько того и другого ему надо смешать, чтобы получить 30 литров 4% молока? Интересно, сколько есть способов решения? (Мой кажется мне неуклюжим.)

Comments

[24816.livejournal.com]

Elementary school kids can only invent the solution based on their intuition. The method can be TAUGHT as part of Algebra course. I don’t remember if we studied Algebra is 7th grade back in Russia. But 8th grade of 10-year-Russian-school might be close to 10th grade of 13-year-US-school.

Here are a couple of more considerations:
http://www.israelnationalnews.com/News/Flash.aspx/138831
http://www.che-be.com/news/2008-08/691/
-FI