HardJava
Java Quiz: advanced memory, threads and modern API
Test your advanced Java knowledge: heap and stack, garbage collector, immutable String, threads, synchronized, volatile, ExecutorService, Optional and records.
Mathematics quizzes
Numbers, geometry, logic
Mathematics is the language of the sciences, and this theme covers its main branches: arithmetic and prime numbers, fractions and percentages, algebra and equations, the geometry of triangles and circles, probability, and great names from Euclid and Pythagoras to Euler and Gauss. Along the way you meet pi, the Fibonacci sequence, classic theorems and the logic puzzles that make the subject fun.
Whether you are brushing up on school basics or just enjoy a good brain teaser, this mathematics quiz tests your number sense. Every quiz is free, spans five difficulty levels from very easy to expert, and gives you an explanation after each answer so you understand the reasoning, not just the result.
Quizzes
MediumJava
Java Quiz: OOP, inheritance, interfaces and collections
Test your object-oriented programming knowledge in Java: inheritance, interfaces, encapsulation, static, exceptions, collections, generics and equals.
EasyJava
Java Quiz: language basics, types and syntax
Test your Java basics: its creator, the JVM, the JDK and the JRE, the boolean and char types, String, arrays, the main method and class names.
Related themes
Frequently asked questions about Mathematics
What does the Pythagorean theorem say?
In a right triangle, the square of the hypotenuse, the side opposite the right angle, equals the sum of the squares of the other two sides. For example, a triangle with sides 3, 4 and 5 is a right triangle, because 3² + 4² = 9 + 16 = 25 = 5².
What is a prime number?
A prime number is a whole number greater than 1 whose only divisors are 1 and itself. The first primes are 2, 3, 5, 7, 11 and 13, and 2 is the only even prime. Since Euclid, mathematicians have known that there are infinitely many primes.
What does the number pi represent?
Pi is the ratio of a circle's circumference to its diameter, the same for every circle. Its approximate value is 3.14159. It is an irrational number: its decimal expansion never ends and never settles into a repeating pattern. Pi also appears in the area of a circle, pi times the radius squared.