1. David received an inheritance of $50,000. His financial advisor suggests that he invest this in three mutual funds: a money-market fund, a blue-chip stock fund, and a high-tech stock fund. The advisor estimates that the money-market fund will return 5% over the next year, the blue-chip fund 9%, and the high-tech fund 16% (all simple interest). David wants a total first-year return of $4000 in interest income. To avoid excessive risk, he decides to invest three times as much in the money-market fund as in the high-tech stock fund. How much should be invested in each fund?

2. At a college production of A Streetcar Named Desire, 400 tickets were sold. The ticket prices were $8, $10, and $12, and the total income from the ticket sales was $3700. How many tickets of each type were sold if the combined number of $8 and $10 tickets sold was 7 times the number of $12 tickets sold.

3. A hospital dietician must plan a lunch menu that provides 485 calories, 41.5 g of carbohydrates, and 35 mg of calcium. A 3-oz serving of broiled ground beef contains 245 Cal, 0 g of carbohydrates and 9 mg of calcium. One baked potato contains 145 cal, 34 g of carbohydrates, and 8 mg of calcium. A one-cup serving of strawberries contains 45 cal, 10 g of carbohydrates, and 21 mg of calcium. How many servings of each are required to provide the desired nutritional values?