Question Each letter stands for a distinct digit, and if letters are different, so are the digits they represent. What digit is E?

Two trains, each traveling at a speed of are headed toward each other on the same track. At the exact moment the trains are apart,

Art gallery problems involve finding an unmoving guard (or guards) who can “see” the entire gallery. A guard is able t

Can Area Reveal Volume? Consider the two shapes inside the two identical cylinders whose radius is equal to its height.

Can a 10 x 10 grid of cells be covered by 25 1 x 4 pieces?

All four Kings from a deck of cars are placed face down on a table in a random order. You select two of them, and if both are the

A system of two symmetrical, identical, water-filled jars is fixed on a turntable. Each jar has a cork—attached to the bottom by

Question Two of the following statements are true and the other one is false: This statement is true. The first statement is false

True or False? The sum of two consective triangular numbers is always a square numbers!

Which string will break first? a. Horizontal String!, b. Vertical String!, c. Both will break at the same time

If a number n can be factored as a×b then n will appear in row a+b-1. For example the number 6 appears in row 1+6-1=6 but also ro

Nine consecutive integers are placed in the squares of a 3x3 grid. Every column, every row, and every diagonal add up to the same