9515 | Science: Mathematics | True / False | Medium | Aleph-nought is the cardinality of the set of all natural numbers. |
9514 | Science: Mathematics | Multiple Choice | Easy | What comes after a Million, a Billion, and a Trillion? |
9513 | Science: Mathematics | True / False | Hard | Set theory was founded by a single paper in 1799 by Carl Friedrich Gauss: "On a Property of the Collection of All Real Algebraic Numbers". |
9512 | General Knowledge | Multiple Choice | Easy | What is the perimeter of a circle more commonly known as? |