MATH COUNTS 2008 School Competition Countdown Round
1. The Quill and Scroll is a stationery shop. Its stock and sales for May are listed in the table shown. What percent of its sales were not pens or pencils? ? Other 35 Pencils 38 Pens % of May Sales Item
6. The 22 members of Troop 71 and their leader, Dave, are planning an overnight camping trip. Dave is planning to make hamburgers, and his recipe calls for 1 pound of beef per 4 burgers. Assuming each person eats one burger, how many pounds of beef should he purchase to serve the troop, himself and the 3 chaperones? Express your answer as a decimal to the nearest tenth.
12. Students in the 2nd grade at West ES were asked how many minutes they spent doing homework last night. The data is displayed in this box-and-whisker plot. What is the range of the data, in minutes?
22. In an election, 1,200 total votes were cast for the 3 candidates. The second-place candidate received 125 fewer votes than the winner and 200 votes more than the third-place candidate. How many votes did the winner receive?
28. In Perfectville, the streets are all 20 feet wide and the blocks they enclose are all squares of side length 400 feet, as shown. Sarah runs around the block on the 400-foot side of the street, while Sam runs on the opposite side of the street. How many more feet than Sarah does Sam run for every lap around the block?
30. A rectangular array of chairs is an arrangement of the chairs in rows and columns such that each row contains the same number of chairs as every other row and each column contains the same number of chairs as every other column. If there must be at least two chairs in every row and column and all of the chairs in the room must be included, how many arrays are possible in a classroom containing 36 chairs? Note that 12 rows of 3 chairs is different from 3 rows of 12 chairs.
32. Ellen baked 2 dozen cupcakes of which half contained chocolate, two-thirds contained raisins, one-fourth contained chocolate chips and one-sixth contained nuts. What is the largest possible number of cupcakes that had none of these ingredients?
37. An arc of 55 degrees on circle A has the same length as an arc of 40 degrees on circle B. What is the ratio of the area of circle A to the area of circle B? Express your answer as a common fraction.
39. Approximately 70% of the earth’s surface is covered with water. Twenty-five percent of the remaining surface is green space. What percent of the earth’s surface is not covered with water and is not green space? Express your answer to the nearest tenth.
41. A 4-foot by 8-foot rectangular piece of plywood will be cut into 4 congruent rectangles with no wood left over and no wood lost due to the cuts. What is the positive difference, in feet, between the greatest possible perimeter of a single-cut piece and the least possible perimeter of a single-cut piece?
44. One hundred people were surveyed. Of these, 87 indicated they liked Mozart and 70 indicated they liked Bach. What is the minimum number of people surveyed who could have said they liked both Mozart and Bach?
56. A right rectangular prism has a base area one-quarter the base area of a larger right rectangular prism. The height of the smaller prism is half the height of the larger one. What is the ratio of the volume of the smaller prism to the volume of the larger prism? Express your answer as a common fraction.
58. In triangle ABC, the measure of angle A is x degrees, the measure of angle B is 2 x degrees and the measure of angle C is 5 x degrees. What is the value of x ? Express your answer as a decimal to the nearest tenth.