Indices

  • Mega Quadratic Equations
    problem

    Mega quadratic equations

    Age
    14 to 18
    Challenge level
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    What do you get when you raise a quadratic to the power of a quadratic?

  • Negative 3 to the power of negative 3.
    problem

    Negative powers

    Age
    14 to 18
    Challenge level
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    What does this number mean? Which order of 1, 2, 3 and 4 makes the highest value? Which makes the lowest?

  • Big, Bigger, Biggest
    problem

    Big, bigger, biggest

    Age
    16 to 18
    Challenge level
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    Which is the biggest and which the smallest of $2000^{2002}, 2001^{2001} \text{and } 2002^{2000}$?

  • Sums of Squares
    problem

    Sums of squares

    Age
    16 to 18
    Challenge level
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    Can you prove that twice the sum of two squares always gives the sum of two squares?
  • Telescoping series
    problem

    Telescoping series

    Age
    16 to 18
    Challenge level
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    Find $S_r = 1^r + 2^r + 3^r + ... + n^r$ where r is any fixed positive integer in terms of $S_1, S_2, ... S_{r-1}$.

  • Climbing Powers
    problem

    Climbing powers

    Age
    16 to 18
    Challenge level
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    Does it make any difference how we write powers of powers? 

  • Giants
    problem

    Giants

    Age
    16 to 18
    Challenge level
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    Which is the bigger, 9^10 or 10^9 ? Which is the bigger, 99^100 or 100^99 ?

  • Powerful Factors
    problem

    Powerful factors

    Age
    16 to 18
    Challenge level
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    Use the fact that: x²-y² = (x-y)(x+y) and x³+y³ = (x+y) (x²-xy+y²) to find the highest power of 2 and the highest power of 3 which divide 5^{36}-1.
  • Tens
    problem

    Tens

    Age
    16 to 18
    Challenge level
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    When is $7^n + 3^n$ a multiple of 10? Can you prove the result by two different methods?
  • Cube Roots
    problem

    Cube roots

    Age
    16 to 18
    Challenge level
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    Evaluate without a calculator: (5 sqrt2 + 7)^{1/3} - (5 sqrt2 - 7)^1/3}.