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2014/15 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. When the repeating decimal 0.6‾0.\overline{6} is divided by the repeating decimal 0.3‾0.\overline{3}, the quotient is

  2. The number of two-digit positive integers such that the sum of the two digits is 1212 is

  3. Let a>b>0a > b > 0 be prime numbers. Of the following five numbers, the one which cannot be equal to a−ba - b is

  4. Chau and Matt are picking berries. On Monday Matt picks twice as many kilograms of berries as Chau does, and on Tuesday Chau picks twice as many kilograms of berries as Matt does. Between them, they pick a total of 3030 kilograms of berries over the two days. The number of kilograms of berries Chau picks over the two days is

  5. For every set of five of the numbers 11, 22, …, 20142014, Lac writes down the smallest of the five numbers. The largest number she writes down is

  6. The sum of four consecutive integers is nn. The largest of these four numbers is

  7. Let f(n)=2n3f(n) = 2n^3 for any positive integer nn. For any odd number m≥3m \ge 3, the largest positive integer kk such that 2k2^k divides f(f(f(m)))f(f(f(m))) is

  8. Let ff be a function such that f(x)+3f(1x)=x2f(x) + 3f\bigl(\dfrac{1}{x}\bigr) = x^2 for any nonzero real number xx. Then the value of f(−3)f(-3) is

  9. The number of integer pairs (m,n)(m, n) such that mn=m+nmn = m + n is

  10. The number of five-digit positive integers such that the digits are alternately odd and even (either odd-even-odd-even-odd or even-odd-even-odd-even) is

  11. Let aa, bb and cc be real numbers such that a+b+c=5a + b + c = 5 and 1b+c+1c+a+1a+b=6\dfrac{1}{b+c} + \dfrac{1}{c+a} + \dfrac{1}{a+b} = 6. The value of ab+c+bc+a+ca+b\dfrac{a}{b+c} + \dfrac{b}{c+a} + \dfrac{c}{a+b} is

  12. PP is a point inside an acute triangle ABCABC. DD, EE and FF are the feet of the perpendiculars from PP on BCBC, CACA and ABAB respectively. If BD=1BD = 1, DC=10DC = 10, CE=6CE = 6, EA=9EA = 9 and AF=13AF = 13, the length of FBFB is

  13. Three candles which can burn for 3030, 4040 and 5050 minutes respectively are lit at different times. All three candles are burning simultaneously for 1010 minutes, and there is a total of 2020 minutes in which exactly one of them is burning. The number of minutes in which exactly two of them are burning is

  14. PP is a point inside a convex quadrilateral ABCDABCD of area 168168 such that PA=9PA = 9, PB=PD=12PB = PD = 12 and PC=5PC = 5. The perimeter of the quadrilateral is

  15. For any real numbers xx and yy, the minimum value of x4−5x2+y2+2x+2y+2xy+6x^4 - 5x^2 + y^2 + 2x + 2y + 2xy + 6 is

  16. Four cages are arranged in a 2×22 \times 2 formation. Each cage contains some chickens and some rabbits (some cages may contain only chickens or only rabbits). The total number of heads in the two cages in the first row is 6060. The total number of legs in the two cages in the second row is 240240. The total number of heads in the two cages in the first column is 7070. The total number of legs in the two cages in the second column is 230230. The minimum number of animals in all four cages is

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