Question 1159726
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The ratio in which the two kinds of cookies must be mixed is exactly determined by where the price per kg of the mixture lies between the prices per kg of the two kinds of cookies.<br>
By whatever method you choose, determine that $3.56 is 2/5 of the way from $3.30 to $3.95.  (For example, $3.30 to $3.95 is a difference of $0.65; $3.30 to $3.56 is a difference of $0.26; $0.26/$0.65 = 2/5.)<br>
That means the more expensive cookies have to be 2/5 of the mixture; which of course means 3/5 of the mixture is the less expensive cookies.<br>
ANSWER: 3/5 of 30kg, or 18kg, of the $3.30 per kg cookies, the other 12kg of the $3.95 per kg cookies.<br>