Puzzle 1
This arrow is currently pointing from South to North.
Move one line and add one other to leave the arrow pointing from East to West.
Puzzle Copyright © Lloyd King
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
We have been quite lucky with the weather recently, it has got steadily warmer each day over the last five days.
By this, I mean that the midday temperature rose by the same amount each day.
The average midday temperature was 2 °C, and I know that it was below freezing (< 0 °C) on two of the days.
I also know the product of the temperatures was over 500 but below 2,000 and each daily midday temperature was an integer.
What were the last 5 midday temperatures?
Puzzle 4
What number comes next in this sequence:
914275 · 94275 · 9475 · 975 · ?