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2009/10 AHSMC Part 1

All 16 problems. Take it as a timed test — 1:20:00 on the clock, scored the way the AMC is — or read through the problems and open any of them for its worked solution.

16 problems · 6 points correct, 1.5 for blank, 0 for wrong

  1. If 2x=3y2^x = 3^y, then 4x4^x is equal to

  2. Caroline bought some bones for her 77 dogs. Had she owned 88 dogs, she could have given each the same number of bones. As it was, she needed two more bones to give each dog the same number of bones. The number of bones she could have bought was

  3. Ace calculates the average of all the integers from 11 to 100100. Bea calculates the average of all the integers from 10011001 to 11001100 and subtracts 10001000. Cec calculates the average of all the integers from 10000011000001 to 10001001000100 and subtracts 10000001000000. The largest answer is given by

  4. A large rectangular gymnasium floor is covered with unit square tiles, most of them blank, in the pattern shown in the diagram below. Of the following fractions, the one nearest to the fraction of tiles which are not blank is

    Figure for this problem

  5. The number of integers between 11 and 20092009 inclusive which can be expressed as the difference of the squares of two integers is

  6. Among the positive integers with six digits in their base-1010 representation, the number of those whose digits are strictly increasing from left to right is

  7. The number of arrangements of the letters AABBCC in a row such that no two identical letters are adjacent is

  8. If 220092^{2009} has mm digits and 520095^{2009} has nn digits in their base-1010 representations, then the value of m+nm + n is

  9. An equilateral triangle has area 232\sqrt{3}. From the midpoint of each side, perpendiculars are dropped to the other two sides. The area of the hexagon formed by these six lines is

  10. Two sides of an obtuse triangle of positive area are of length 55 and 1111. The number of possible integer lengths of the third side is

  11. Q(x)Q(x) is a polynomial with integer coefficients such that Q(9)=2009Q(9) = 2009. If pp is a prime number such that Q(p)=392Q(p) = 392, then pp can

  12. A parallelogram has two opposite sides 55 centimetres apart and the other two opposite sides 88 centimetres apart. Then the area, in square centimetres, of the parallelogram

  13. The number of positive integers nn such that n+n+⋯+n<10\sqrt{n + \sqrt{n + \cdots + \sqrt{n}}} < 10 for any finite number of square root signs is

  14. A chord of a circle divides the circle into two parts such that the squares inscribed in the two parts have areas 1616 and 144144 square centimetres. In centimetres, the radius of the circle is

  15. The number of prime numbers pp such that 2p+p22^p + p^2 is also a prime number is

  16. Suppose that 2−992 - \sqrt{99} is a root of x2+ax+bx^2 + ax + b where bb is a negative real number and aa is an integer. The largest possible value of aa is

0 of 16 answered. Each problem left blank still scores 1.5 points.