Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
MATHCOUNTS Countdown Round 1. Half of 12 is equal to what number? Answer: 6 2. What is the smallest positive integer that can be added to 100 to make a multiple of 3? Answer: 2 3. Five U.S. coins are worth a total of 35 cents. How many of the coins are dimes? Answer: 2 coins 4. How much more than 42 is 3 3? Answer: 11 5. What is the greatest common factor of 40 and 48? Answer: 8 6. What is the sum of the number of faces and edges of a triangular prism? Answer: 14 7. The value of eight nickels and six dimes is the same as four nickels and how many dimes? Answer: 8 dimes 8. Fred has 2 yellow, 2 red and 2 green tokens. One red token is equal to 9 green tokens. One yellow token is equal to 3 green tokens. Fred converts all of his tokens to green tokens. How many green tokens does he have? Answer: 26 tokens 9. If the last two digits of 9567 were interchanged, how much larger would the new number be? Answer: 9 10. The average of five numbers is 10. Four of the numbers are 10, 10, 10 and 9. What is the value of the fifth number? Answer: 11 11. In the figure shown, polygons ABCD, CDEF and DEGH are squares. The length of segment FG is 10 cm. How many square centimeters are in the area of E F hexagon C ABFGHD? D B A G H Answer: 75 square centimeters 12. How many positive integers are less than 10p? Answer: 31 integers 1 6 13. In training, Petra runs of a mile in 60 seconds. At this rate, how many seconds does it take Petra to complete a run of 1 mile? Answer: 360 seconds 14. What is the remainder when 4697 is divided by 9? Answer: 8 15. How many more boxes are needed if 70 ornaments are packaged in boxes that each hold 5 ornaments rather than boxes that each hold 7 ornaments? Answer: 4 boxes 16. What reduced fraction is equivalent to 25%? 1 Answer: 4 22. The area of a square is 49 square centimeters. How many centimeters are in the length of a side of the square? Answer: 7 centimeters 17. At which of the following stores is the average cost per pencil the least? Store A: 17 pencils for $1.70 Store B: 7 pencils for $1.40 Store C: 5 pencils for $0.85 Answer: Store A 18. In any month with a “Friday the 13th,” what day of the week is the first day of the same month? Answer: Sunday 19. Each side of pentagon ABCDE has length less than or equal to 7 units, AB = 5 units and BC = 4 units. How many units are in the greatest possible perimeter of ABCDE? Answer: 30 units 20. Two figures each have a perimeter of 80 feet. One is a square and one is a rectangle with dimensions of 10 feet by 30 feet. What is the positive difference in the number of square feet of their areas? Answer: 100 square feet 21. What is the greatest integer 17 less than ? 4 Answer: 5 22. Using two distinct members of the set {0, 1, 2, 3}, how many different sums can be found? Answer: 5 sums 23. How many integers between 20 and 90 are perfect squares? Answer: 5 integers 24. What is the greatest two-digit multiple of 4? Answer: 96 25. Joshua’s restaurant bill is $10. To calculate the tip, he calculates 15% of the value of the bill and then rounds up to the nearest dollar. What was the amount of his tip? Answer: 2 dollars 26. What is the sum: –4 + –3 + –2 + ... + 3 + 4 + 5 + 6? Answer: 11 27. The ratio of x to 10 is equal to the ratio of 12 to 30. What is the value of x? Answer: 4 28. What is the units digit of the product of the first four positive integers? Answer: 4 29. Evaluate (x + y)(x – y) when x = 15 and y = 5. Answer: 200 30. How many degrees are in each interior angle of an equilateral triangle? Answer: 60 degrees 31. If 75 seeds are planted and 25 of the seeds are germinating, what is the ratio of seeds germinating to seeds planted? Express your answer as a reduced fraction. 1 Answer: 3 32. The scale of a backpacker’s map is “1 cm on the map = 240 meters on the ground.” How many kilometers long is a hike that measures 10 cm on the map? Express your answer as a decimal to the nearest tenth. Answer: 2.4 kilometers 33. Mississippi was one of the 10 states to lose a Congressional seat based on the 2000 Census. What percent of the 50 states did not lose a Congressional seat? Answer: 80 percent 34. Let y = 2 + 3x. How much greater is y when x = 3 than when x = 2? Answer: 3 35. Ben flips a fair nickel two times. What is the probability that Ben flips a Head and then a Tail? Express your answer as a reduced fraction. Answer: 1 4 36. Mary jogs 12 miles in 2 hours. On average, how many minutes does it take her to jog one mile? Answer: 10 minutes 37. With one skein of wool yarn, Sharon can knit 3 inches of a scarf that is 9 inches wide. What is the least whole number of skeins with which she can knit a scarf that is 6 inches wide and 27 inches long? Answer: 6 skeins 38. Two positive integers have a sum of 28 and are in the ratio 3:4. What is the least of these two integers? Answer: 12 39. Marie owns 11 department stores. Each store has 12 shelves for towels. What is the total number of shelves for towels? Answer: 132 shelves 40. When 5 is subtracted from three times a particular number, the result is 13. What is the number? 3× 5 = 13 Answer: 6 41. The Battling Hummingbirds have won 40% of their first 60 games. If they win their next 12 games in a row, what percent of all of their games will they have won? Answer: 50 percent 42. In box A, there are four more pennies than in box B. The total number of pennies in boxes A and B is 34. What is the number of pennies in box A? Answer: 19 pennies 43. What is the sum of the first five positive odd integers? Answer: 25 44. What number is one hundred less than one thousand thirtythree? Answer: 933 45. Katrina can bicycle 50 miles in four hours. At the same speed, how many miles does she bicycle in six hours? Answer: 75 miles 46. What is the least positive integer that has exactly three distinct factors? Answer: 4 47. The total value of 90 pennies, 20 dimes and 12 quarters is what percent of the value of a ten-dollar bill? Answer: 59 percent 48. Solve for x: 18 x = 10 + x. Answer: 4 49. What is the number of degrees in the measure of angle ABD in square ABCD? A B D C Answer: 45 degrees 50. What is the units digit of 64? Answer: 6 51. Triangle ABC is isosceles with angle B congruent to angle C. The measure of angle C is four times the measure of angle A. What is the number of degrees in the measure of angle B? Answer: 80 degrees 52. What integer is closest 100 to ? 7 Answer: 14 53. What is the largest three-digit multiple of 2? Answer: 998 54. The Carters had a 10-foot by 10-foot patio built at a cost of $2200. How many dollars per square foot did the patio cost to build? Answer: 22 dollars per sq ft 55. What is the decimal 11 equivalent of ? Express 4 your answer to the nearest hundredth. Answer: 2.75 56. The ratio of the measures of two complementary angles is 2:1. What is the measure, in degrees, of the larger angle? Answer: 60 degrees 57. From a one-meter piece of yarn, Chris cuts a 31.5 cm piece and a 35.5 cm piece. In centimeters, how much yarn is left? Answer: 33 centimeters 58. Simplify: 7 103 + 5 102 4 101 + 7 100. Answer: 7467 59. A stair-step exercise machine indicates that Leon burns 180 calories in 12 minutes. At the same rate, how many calories would Leon burn in a 4-minute workout? Answer: 60 calories 60. If y = x2 1, what is the value of y when x = 1? Answer: 0 61. Four friends are in line for movie tickets. Rick is somewhere behind Tom, but ahead of Mark. James and Tom are separated by one person. Who is last in line? Answer: Mark 62. Steven is making a scale drawing of his living room. He is using a scale of 1/4 in = 1 ft. In the drawing, how many inches will represent the length of a 6-foot long couch? Express your answer as a decimal to the nearest tenth. Answer: 1.5 inches 63. The ages, in years, of the eight people in the math club are: 12, 12, 12, 12, 13, 13, 14, 14. What is the mode of the ages? Answer: 12 years 64. What is the greatest prime factor of 10!? Answer: 7 65. Rebecca remembered the first 6 digits of a friend’s 7-digit phone number. If she randomly selects a digit to fill the last digit she can’t remember, what is the probability she will dial the correct number? Express your answer as a common fraction. Answer: 1 10 66. Fifty percent of what number is 12? Answer: 24 67. What is the number of square centimeters in the area of a circle with radius 4 cm? Express your answer is terms of p. Answer: 16p square centimeters 68. A candy company puts 21 candies in each bag. There are only red and blue candies in each bag. For every 2 red candies in a bag there are 5 blue candies. How many red candies are in each bag? Answer: 6 candies 69. What is the value of 52 32? Answer: 16 70. How many triangles of any size are in this figure? Answer: 5 triangles 71. What is 150% of 26? Answer: 39 72. In how many ways can a pair of students be selected from a group of four students? Answer: 6 ways 73. In the formula d = rt, what is the value of r if d = 60 and t = 4? Answer: 15 74. On average, each American consumes 286 eggs per year. What is the number of years it would take, at this rate, for an American to eat 2000 eggs? Express your answer to the nearest whole number. Answer: 7 years 75. Of the 80 students at camp, 40% of them are male. How many female students are at camp? Answer: 48 female students 76. One fair standard six-sided die is rolled. What is the probability of rolling a number greater than 4? Express your answer as a reduced fraction. Answer: 1 3 77. What is the positive difference between 32 and 23? Answer: 1 78. Jane turns 15 in the year 2008. In what year was she born? Answer: 1993 79. A printer prints 17 pages per minute. How many minutes will it take to print 200 pages? Express your answer to the nearest whole number. Answer: 12 minutes 80. Jenna is at a fair with 4 friends. They all want to ride the roller coaster, but only 3 people can fit in a car. How many different groups of 3 can the 5 of them make? Answer: 10 groups 81. What is the value of the following expression: 10 – 9 + 8 – 7 + … + 4 – 3 + 2 – 1? Answer: 5 82. A three-digit integer will be chosen at random from all possible positive three-digit integers. What is the probability that the number’s units digit will be less than 5? Express your answer as a common fraction. 1 Answer: 2 83. If value of + 5 = 18, what is the + ? Answer: 26 84. How many factors does 20 have? Answer: 6 factors 85. Kaya ate 60 cookies over a 5-minute period. On average, how many cookies did she eat each minute? Answer: 12 cookies 86. What is the average of 3, 4, 5 and 8? Answer: 5 87. If two different numbers are chosen from the set {0, 4, 6, 20}, and the smaller number is subtracted from the larger number, what is the smallest possible result? Answer: 2 88. The area of a circle is 49p square units. What is the radius of the circle, in units? Answer: 7 units 89. What is the least common multiple of 3, 5 and 6? Answer: 30 90. If 3 × + 5 = 29, what number must be placed in the square? Answer: 8 91. A hot air balloon is 10 feet off the ground now and is rising at a constant rate of 2 feet per second. What is the height of the balloon, in feet, after 25 more seconds? Answer: 60 feet 92. What fraction of 2 feet is 3 inches? Express your answer as a reduced fraction. 1 Answer: 8 93. The three-digit integer 63_ is a multiple of 3. What is the greatest possible digit that can be placed in the blank? Answer: 9 94. The probability that Asha 4 will lose the game is . What is 9 the probability Asha will not lose the game? Express your answer as a reduced fraction. 5 Answer: 9 95. What is the value of 5!? Answer: 120 96. Robert reads 90 pages per hour. How many 270-page books can he read in six hours? Answer: 2 books 97. Pencils come in a package holding 10 pencils. Rina’s teacher bought 23 packages of pencils. How many pencils did she buy? Answer: 230 pencils A 98. On a protractor, ray BA goes through the 85-degree mark B and ray BC goes through the 30-degree mark. What is the measure, in degrees, of angle ABC? C Answer: 55 degrees 99. What is the sum of the first five positive even integers? Answer: 30 100. Two sides of an isosceles triangle are 15 cm and 10 cm. What is the greatest possible perimeter of this triangle, in centimeters? Answer: 40 centimeters 101. What is the sum of the greatest possible three-digit integer and the greatest possible two-digit integer? Answer: 1098 102. What is the ratio of one interior angle of an equilateral triangle to one interior angle of a square? Express your answer as a reduced fraction. 2 Answer: 3 103. What is the greatest possible three-digit number that is divisible by 3 and divisible by 6? Answer: 996 104. How many obtuse interior angles are in an obtuse triangle? Answer: 1 angle