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  • 1,198 problems
  • 9 difficulty levels
  • +5 to +405 XP per problem
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All problems

Showing 865–912 of 1,198

  • 6.67Functions

    Locked

    A sum of sines equals a cosine

    Difficulty 6 of 9+180 XP

  • 6.68Geometry

    Locked

    The shortest broken line

    Difficulty 6 of 9+180 XP

  • 6.69Probability

    Locked

    A meeting with unequal patience

    Difficulty 6 of 9+180 XP

  • 6.70Equations

    Locked

    A palindromic quartic equation

    Difficulty 6 of 9+180 XP

  • 6.71Calculus

    Locked

    A parabola, a tangent and the x-axis

    Difficulty 6 of 9+180 XP

  • 6.72Geometry

    Locked

    A section of a cube

    Difficulty 6 of 9+180 XP

  • 6.73Combinatorics

    Locked

    A committee with a chairwoman

    Difficulty 6 of 9+180 XP

  • 6.74Calculus

    Locked

    The largest cone in a sphere

    Difficulty 6 of 9+180 XP

  • 6.75Geometry

    Locked

    A trapezoid with two circles

    Difficulty 6 of 9+180 XP

  • 6.76Algebra

    Locked

    From fourth powers to cubes

    Difficulty 6 of 9+180 XP

  • 6.77Functions

    Locked

    An odd periodic function

    Difficulty 6 of 9+180 XP

  • 6.78Arithmetic

    Locked

    Pairs with a common multiple

    Difficulty 6 of 9+180 XP

  • 6.79Probability

    Locked

    Who rolls first

    Difficulty 6 of 9+180 XP

  • 6.80Algebra

    Locked

    A non-symmetric expression in two roots

    Difficulty 6 of 9+180 XP

  • 6.81Calculus

    Locked

    Three roots of a cubic

    Difficulty 6 of 9+180 XP

  • 6.82Arithmetic

    Locked

    Digit sum and eleven

    Difficulty 6 of 9+180 XP

  • 6.83Combinatorics

    Locked

    Coefficients of even powers

    Difficulty 6 of 9+180 XP

  • 6.84Equations

    Locked

    A product of four brackets

    Difficulty 6 of 9+180 XP

  • 6.85Functions

    Locked

    A sine curve and a line

    Difficulty 6 of 9+180 XP

  • 6.86Geometry

    Locked

    A triangle on the foci of an ellipse

    Difficulty 6 of 9+180 XP

  • 6.87Logic

    Locked

    A cyclic conjunction of disjunctions

    Difficulty 6 of 9+180 XP

  • 6.88Algebra

    Locked

    A complex number and its reciprocal

    Difficulty 6 of 9+180 XP

  • 6.89Calculus

    Locked

    An integral with an absolute value and a cosine

    Difficulty 6 of 9+180 XP

  • 6.90Geometry

    Locked

    The angle between lateral faces

    Difficulty 6 of 9+180 XP

  • 6.91Probability

    Locked

    No three heads in a row

    Difficulty 6 of 9+180 XP

  • 6.92Algebra

    Locked

    A long sum of fractions with square roots

    Difficulty 6 of 9+180 XP

  • 6.93Functions

    Locked

    A function composed with itself

    Difficulty 6 of 9+180 XP

  • 6.94Arithmetic

    Locked

    How many twos are hidden

    Difficulty 6 of 9+180 XP

  • 6.95Combinatorics

    Locked

    Stairs without two long steps in a row

    Difficulty 6 of 9+180 XP

  • 6.96Equations

    Locked

    Nested square roots and integer solutions

    Difficulty 6 of 9+180 XP

  • 6.97Calculus

    Locked

    A sum of products of neighbouring terms

    Difficulty 6 of 9+180 XP

  • 6.98Geometry

    Locked

    A point inside a square

    Difficulty 6 of 9+180 XP

  • 6.99Probability

    Locked

    Couples at a round table

    Difficulty 6 of 9+180 XP

  • 6.100Combinatorics

    Locked

    Paths below the diagonal

    Difficulty 6 of 9+180 XP

  • 7.1Calculus

    Locked

    The limit of a rational sequence

    Difficulty 7 of 9+245 XP

  • 7.2Calculus

    Locked

    The derivative of a product at a point

    Difficulty 7 of 9+245 XP

  • 7.3Calculus

    Locked

    The mean value of a root function

    Difficulty 7 of 9+245 XP

  • 7.4Calculus

    Locked

    The sum of two geometric series

    Difficulty 7 of 9+245 XP

  • 7.5Calculus

    Locked

    A square root minus a linear term

    Difficulty 7 of 9+245 XP

  • 7.6Calculus

    Locked

    The slope of a parametric curve

    Difficulty 7 of 9+245 XP

  • 7.7Calculus

    Locked

    A square root of a cubic

    Difficulty 7 of 9+245 XP

  • 7.8Calculus

    Locked

    A series with a product in the denominator

    Difficulty 7 of 9+245 XP

  • 7.9Calculus

    Locked

    An exponential over a logarithm at zero

    Difficulty 7 of 9+245 XP

  • 7.10Calculus

    Locked

    The slope of an implicitly defined curve

    Difficulty 7 of 9+245 XP

  • 7.11Calculus

    Locked

    An antiderivative with a condition

    Difficulty 7 of 9+245 XP

  • 7.12Algebra

    Locked

    When the determinant vanishes

    Difficulty 7 of 9+245 XP

  • 7.13Calculus

    Locked

    A sequence tending to a power of e

    Difficulty 7 of 9+245 XP

  • 7.14Calculus

    Locked

    The derivative of an inverse function

    Difficulty 7 of 9+245 XP