Review Unit 8 - Weighted Averages

A solution with 24% swag juice was mixed with 40 oz. of a solution that had 42% swag juice. To tone down the swag, how much of the 24% solution must be added to obtain a solution with just 40% swag juice?

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A solution with 14% HIM is mixed with a solution that has 44% HIM. How much of each solution must be used to create a solution of 72 mL with 25% HIM? Enter the answer as an ordered pair: (x,y)

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Justin is now 3 times as old as Arthur. In 10 years, Justin will be twice as old as Arthur will be then. How old is Justin now?

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Selma is now 3 times as old as Joyce. Four years ago, Selma was 4 times as old was Joyce was then. How old is Selma now?

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Mrs. Sanford is three times as old as Mrs. Fox. Eight years from now, Mrs. Sanford’s age will exceed twice Mrs. Fox’s age at that time by 14 years. How old is Mrs. Fox now?

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Father is twice as old as his son. 20 years back, father was twelve times as old as his son. What is the present age of father?

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Two trains leave at the same time in opposite directions. The CheeChee Train is traveling at 200 feet/second while the ChewChew Train is traveling at 350 feet/second. How many seconds will elapse before the trains are 165000 feet apart?

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A total of $16,000 was invested at annual interest rates of 4% and 7%. If the return was $940, how much was invested in the 4% account?

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A total of $16,000 was invested at annual interest rates of 4% and 7%. If the return was $940, how much was invested in the 7% account?

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A total of $9,000 was invested at annual interest rates of 3% and 4%. If the return was $350, how much was invested in the 3% account?

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