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  • 1,198 problems
  • 9 difficulty levels
  • +5 to +405 XP per problem
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Showing 49–96 of 1,198

  • 1.49Logic

    Locked

    Gauss's sum

    Difficulty 1 of 9+5 XP

  • 1.50Equations

    Locked

    Variable on both sides

    Difficulty 1 of 9+5 XP

  • 1.51Combinatorics

    Locked

    Seating four

    Difficulty 1 of 9+5 XP

  • 1.52Algebra

    Locked

    Quadratic equation I

    Difficulty 1 of 9+5 XP

  • 1.53Arithmetic

    Locked

    Primes below 20

    Difficulty 1 of 9+5 XP

  • 1.54Geometry

    Locked

    Area of a circle

    Difficulty 1 of 9+5 XP

  • 1.55Functions

    Locked

    Function value

    Difficulty 1 of 9+5 XP

  • 1.56Probability

    Locked

    Sum of seven

    Difficulty 1 of 9+5 XP

  • 1.57Combinatorics

    Locked

    Number of subsets

    Difficulty 1 of 9+5 XP

  • 1.58Algebra

    Locked

    System: sum and difference

    Difficulty 1 of 9+5 XP

  • 1.59Equations

    Locked

    Exponent of two

    Difficulty 1 of 9+5 XP

  • 1.60Arithmetic

    Locked

    Digit sum

    Difficulty 1 of 9+5 XP

  • 1.61Geometry

    Locked

    Hexagon angle

    Difficulty 1 of 9+5 XP

  • 1.62Functions

    Locked

    Quadratic function

    Difficulty 1 of 9+5 XP

  • 1.63Probability

    Locked

    A heart card

    Difficulty 1 of 9+5 XP

  • 1.64Combinatorics

    Locked

    Choose 3 from 10

    Difficulty 1 of 9+5 XP

  • 1.65Algebra

    Locked

    Negative root

    Difficulty 1 of 9+5 XP

  • 1.66Arithmetic

    Locked

    Divisible by all

    Difficulty 1 of 9+5 XP

  • 1.67Combinatorics

    Locked

    Trailing zeros of 10!

    Difficulty 1 of 9+5 XP

  • 1.68Geometry

    Locked

    Triangle area

    Difficulty 1 of 9+5 XP

  • 1.69Equations

    Locked

    Linear equation

    Difficulty 1 of 9+5 XP

  • 1.70Functions

    Locked

    Composed function

    Difficulty 1 of 9+5 XP

  • 1.71Probability

    Locked

    At least one head

    Difficulty 1 of 9+5 XP

  • 1.72Combinatorics

    Locked

    Anagrams of MAMA

    Difficulty 1 of 9+5 XP

  • 1.73Algebra

    Locked

    Quadratic equation II

    Difficulty 1 of 9+5 XP

  • 1.74Arithmetic

    Locked

    Sum of odds

    Difficulty 1 of 9+5 XP

  • 1.75Geometry

    Locked

    Cylinder volume

    Difficulty 1 of 9+5 XP

  • 1.76Functions

    Locked

    Function within itself

    Difficulty 1 of 9+5 XP

  • 1.77Probability

    Locked

    Three equal dice

    Difficulty 1 of 9+5 XP

  • 1.78Combinatorics

    Locked

    Five-digit, distinct digits

    Difficulty 1 of 9+5 XP

  • 1.79Algebra

    Locked

    A number and its reciprocal

    Difficulty 1 of 9+5 XP

  • 1.80Arithmetic

    Locked

    Number of divisors

    Difficulty 1 of 9+5 XP

  • 1.81Geometry

    Locked

    Octagon angles

    Difficulty 1 of 9+5 XP

  • 1.82Equations

    Locked

    Double root

    Difficulty 1 of 9+5 XP

  • 1.83Functions

    Locked

    Inverse at zero

    Difficulty 1 of 9+5 XP

  • 1.84Probability

    Locked

    Two girls

    Difficulty 1 of 9+5 XP

  • 1.85Combinatorics

    Locked

    Distributing candies

    Difficulty 1 of 9+5 XP

  • 1.86Algebra

    Locked

    Sum of roots

    Difficulty 1 of 9+5 XP

  • 1.87Arithmetic

    Locked

    Last digit of 7¹⁰⁰

    Difficulty 1 of 9+5 XP

  • 1.88Geometry

    Locked

    Inscribed circle

    Difficulty 1 of 9+5 XP

  • 1.89Functions

    Locked

    Sum of cubes

    Difficulty 1 of 9+5 XP

  • 1.90Probability

    Locked

    Matching weekdays

    Difficulty 1 of 9+5 XP

  • 1.91Geometry

    Locked

    Decagon diagonals

    Difficulty 1 of 9+5 XP

  • 1.92Arithmetic

    Locked

    Percentages – discount

    Difficulty 1 of 9+5 XP

  • 1.93Arithmetic

    Locked

    Four Friends

    Difficulty 1 of 9+5 XP

  • 1.94Arithmetic

    Locked

    Days of the week

    Difficulty 1 of 9+5 XP

  • 1.95Logic

    Locked

    Copper cables

    Difficulty 1 of 9+5 XP

  • 1.96Fractions

    Locked

    Adding fractions

    Difficulty 1 of 9+5 XP