可汗SAT数学练习：Systems of linear inequalities word problems【4】
17.Aaron is purchasing party hats and fake mustaches for an end of the school year party. He can spend at most $30. Fake mustaches cost $3 each, and party hats cost $2 each. If he must purchase a combination of at least 15 mustaches and party hats, which of the following systems of inequalities best models the relationship between the number of mustaches, m, and party hats, p, described above?
18.A company manufactures cellular phones and laptop computers. The company's daily production of cellular phones, c, must be more than 500,000, and its daily production of laptop computers, l, must be more than 300,000. If the maximum capacity of the company's manufacturing center is no more than 950,000 total cellular phones and laptop computers, which of the following systems of inequalities best models the situation described above?
19.Tony is raising funds for his school soccer team by selling boxes of candy and t-shirts. His goal is to make more than $300 dollars overall. Each box of candy that Tony sells earns him $15, and each t-shirt sold earns him $20. If Tony wants to sell at least as many t-shirts as boxes of candy, then which of the following systems of inequalities best models the relationship between the number of boxes of candy, c, and t-shirts, t, described above?
20.Arturo goes to his neighborhood store to purchase almonds and walnuts for an old family recipe. One pound of almonds costs $2, and one pound of walnuts costs $4. Arturo can spend at most $18 on almonds and walnuts. The graph at left, in the wa-plane, relates the number of pounds, w, of walnuts to the number of pounds, a, of almonds which Arturo can purchase and have enough for his recipe. Which of the following amounts of walnuts and almonds can he purchase?