Difference between revisions of "2014 AIME II Problems"
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+ | Charles has two six-sided die. One of the die is fair, and the other die is biased so that it comes up six with probability <math>\frac{2}{3}</math> and each of the other five sides has probability <math>\frac{1}{15}</math>. Charles chooses one of the two dice at random and rolls it three times. Given that the first two rolls are both sixes, the probability that the third roll will also be a six is <math>\frac{p}{q}</math>, where <math>p</math> and <math>q</math> are relatively prime positive integers. Find <math>p+q</math>. | ||
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[[2014 AIME II Problems/Problem 6|Solution]] | [[2014 AIME II Problems/Problem 6|Solution]] |
Revision as of 12:11, 27 March 2014
2014 AIME II (Answer Key) | AoPS Contest Collections • PDF | ||
Instructions
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Contents
[hide]Problem 1
Abe can paint the room in 15 hours, Bea can paint 50 percent faster than Abe, and Coe can paint twice as fast as Abe. Abe begins to paint the room and works alone for the first hour and a half. Then Bea joins Abe, and they work together until half the room is painted. Then Coe joins Abe and Bea, and they work together until the entire room is painted. Find the number of minutes after Abe begins for the three of them to finish painting the room.
Problem 2
Arnold is studying the prevalence of three health risk factors, denoted by A, B, and C, within a population of men. For each of the three factors, the probability that a randomly selected man in the population has only this risk factor (and none of the others) is 0.1. For any two of the three factors, the probability that a randomly selected man has exactly these two risk factors (but not the third) is 0.14. The probability that a randomly selected man has all three risk factors, given that he has A and B is . The probability that a man has none of the three risk factors given that he doest not have risk factor A is , where and are relatively prime positive integers. Find .
Problem 3
A rectangle has sides of length and 36. A hinge is installed at each vertex of the rectangle, and at the midpoint of each side of length 36. The sides of length can be pressed toward each other keeping those two sides parallel so the rectangle becomes a convex hexagon as shown. When the figure is a hexagon with the sides of length parallel and separated by a distance of 24, the hexagon has the same area as the original rectangle. Find .
Problem 4
The repeating decimals and satisfy
where , , and are (not necessarily distinct) digits. Find the three digit number .
Problem 5
Real numbers and are roots of , and and are roots of . Find the sum of all possible values of .
Problem 6
Charles has two six-sided die. One of the die is fair, and the other die is biased so that it comes up six with probability and each of the other five sides has probability . Charles chooses one of the two dice at random and rolls it three times. Given that the first two rolls are both sixes, the probability that the third roll will also be a six is , where and are relatively prime positive integers. Find .
Problem 7
Problem 8
Problem 9
Problem 10
Problem 11
Problem 12
Problem 13
Problem 14
Problem 15
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.