Puzzle 2
Your objective is to place some diagonal mirrors into the grid.
If a ray of light is shone in to the grid from each of the letters, and allowed to bounce off the internal diagonal mirrors, each will exit the grid at the twin of the letter that it entered the grid. For example, a ray entering at either letter D will bounce off some mirrors and exit the grid at the other letter D.
Each row and each column will contain exactly two of the diagonal mirrors.
Puzzle Copyright © Elliott Line
This puzzle appeared in Mensa's EnigmaSig (196.26) and is used with permission.
Puzzle 3
Can you make this equation correct by moving exactly one matchstick?
Note: this puzzle is not interactive, and the matchsticks cannot be moved. The matchstick layouts for each digit are:
Puzzle 4
My local greengrocer is a would-be mathematician.
She likes to arrange the apples in nice rows.
When she lays the apples in rows of 3, she has one left over.
And, when she lays them in rows of 5, she also has one left over.
Remarkably, she also has one left over when she arranges them in rows of 7 and 9.
But 11 seems to be the magic number, because in rows of 11 there are no apples left over.
How many apples does she have?