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2015/16 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. How many three digit numbers have the product of the three digits equal to 55?

  2. Let mm, nn be positive integers such that 230330=8m9n2^{30}3^{30} = 8^m 9^n. Determine the value of m+nm + n.

  3. The xx-intercept, yy-intercept, and slope of a certain straight line are three nonzero real numbers. The number of negative numbers among these three numbers is:

  4. The length of a certain rectangle is increased by 20%20\% and its width is increased by 30%30\%. Then its area is increased by:

  5. Each of Alan, Bailey, Clara and Diane has a number of candies. Compared with the average of the number of candies each person has, Alan has 66 more than the average, Bailey has 22 more than the average, Clara has 1010 fewer than the average and Diane has kk candies more than the average. Determine kk.

  6. Ellie wishes to choose three of the seven days (Monday, Tuesday, …, Sunday) on which to wash her hair every week, so that she will never wash her hair on consecutive days. The number of ways she can choose these three days is:

  7. How many different sets of two or more consecutive whole numbers have sum 5555?

  8. There are 55 boys and 66 girls in a class. A committee of three students is to be made such that there is a boy and a girl on the committee. In how many different ways can the committee be selected?

  9. In a class with 2020 students, 1414 wear glasses, 1515 wear braces, 1717 wear ear-rings and 1818 wear wigs. What is the minimum number of students in this class who wear all four items?

  10. Each person has two legs. Some are sitting on three-legged stools while the others are sitting on four-legged chairs such that all the stools and chairs are occupied. If the total number of legs is 3939, how many people are there?

  11. The number of integers nn for which the fraction 220155n+1\dfrac{2^{2015}}{5n+1} is an integer is

  12. In the diagram below, which is not drawn to scale, the circles are tangent at AA, the centre of the larger circle is at OO and the lines ABAB and CDCD are perpendicular.

    Figure for this problem

    If EB=3EB = 3 and FC=2FC = 2 then the radius of the smaller circle is

  13. Consider the expansion (1+x+x2+⋯+x50)3=c0+c1x+c2x2+⋯+c150x150. (1 + x + x^2 + \cdots + x^{50})^3 = c_0 + c_1 x + c_2 x^2 + \cdots + c_{150} x^{150}. The value of the coefficient c50c_{50} is

  14. A 10001000 digit number has the property that every two consecutive digits form a number that is a product of four prime numbers. The digit in the 500500th position is

  15. Points EE and FF are on the sides BCBC and CDCD respectively of the parallelogram ABCDABCD such that EBEC=23\dfrac{EB}{EC} = \dfrac{2}{3} and FCFD=14\dfrac{FC}{FD} = \dfrac{1}{4}. Let MM be the intersection of AEAE and BFBF. The value of AMME\dfrac{AM}{ME} is equal to

  16. Each of Alvin, Bob and Carmen spent five consecutive hours composing problems. Alvin started alone, and was later joined by Bob. Carmen joined in before Alvin stopped. When one person was working alone 44 problems were composed per hour. When two people were working together, each only composed 33 problems per hour. When all three were working, each composed only 22 problems per hour. No coming or going occurs during the composition of any problem. At the end, 4646 problems were composed. How many were composed by Bob?

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