2011 AMC 12A Problems

Problem 1

Solution A cell phone plan costs 20 dollars each month, plus cents per text message sent, plus cents for each minute used over hours. In January Michelle sent text messages and talked for hours. How much did she have to pay?

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Problem 2

Solution There are 5 coins placed flat on a table according to the figure. What is the order of the coins from top to bottom?

Problem 3

Solution A small bottle of shampoo can hold 35 milliliters of shampoo, whereas a large bottle can hold 500 milliliters of shampoo. Jasmine wants to buy the minimum number of small bottles necessary to completely fill a large bottle. How many bottles must she buy?

Problem 4

Solution At an elementary school, the students in third grade, fourth grade, and fifth grade run an average of 12, 15, and 10 minutes per day, respectively. There are twice as many third graders as fourth graders, and twice as many fourth graders as fifth graders. What is the average number of minutes run per day by these students?

Problem 5

Solution Last summer 30% of the birds living on Town Lake were geese, 25% were swans, 10% were herons, and 35% were ducks. What percent of the birds that were not swans were geese?

Problem 6

Solution The players on a basketball team made some three-point shots, some two-point shots, and some one-point free throws. They scored as many points with two-point shots as with three-point shots. Their number of successful free throws was one more than their number of successful two-point shots. The team's total score was 61 points. How many free throws did they make?

Problem 7

Solution A majority of the 30 students in Ms. Demeanor's class bought pencils at the school bookstore. Each of these students bought the same number of pencils, and this number was greater than 1. The cost of a pencil in cents was greater than the number of pencils each student bought, and the total cost of all the pencils was 17.71. What was the cost of a pencil in cents?

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Problem 15

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Problem 17

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Problem 18

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Problem 19

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Problem 20

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Problem 21

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Problem 24

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Problem 25

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