Puzzle

Answer all the questions below and press submit to see how many you got right.

id: 20423

What is the probability that of two thrown coins at least one lands on heads? (Answer as a simplified fraction a/b.)

id: 20462

Lester eats half of a cake on the first day. On the second day he eats half of what is left after the first day. On the third day he eats half of what is left after the second day and so on. How much cake is left after day 3 (Answer as a simplified fraction a/b)?

id: 20446
Card image cap

A 3×3 magic square is a 3×3 square containing the numbers between 1 and 9 so that the sum of the numbers in every row, in every column and in the two diagonals is always the same. What is the number in the center of any such magic square? See the picture for a 4×4 magic square. Everything adds up to 34 there.