Six superheroes capture 20 villains. The first captures 1, the second 2, the third 3. The fourth captures more than each of the other five. What is the smallest possible number captured by the fourth?
Inside the cube is an opaque solid pyramid ABCDS with base ABCD. Its apex S is the midpoint of the indicated cube edge. Viewed from above, below, behind, in front, right and left, which drawing never occurs?
A circular carpet lies on a floor of square tiles. Every tile having more than one point in common with the carpet is grey. Which outcome is impossible?
One side of a rectangle has length 5. It can be cut into a square and a rectangle, one of which has area 4. How many different rectangles satisfy this?
A box contains the 900 distinct cards numbered 100 to 999. François draws cards and finds each digit sum. At least how many must he draw to guarantee three with equal digit sums?