**Puzzle 1: **Which number replaces the question mark?**Answer: ****24**

**Explanation: **Working clockwise around the diagram, add the first two numbers together and subtract 3 to give the next number along.

**Puzzle 2: **Which number replaces the question mark?**Answer: ****24**

**Explanation: **In each circle, the number in the lower segment equals twice the difference between the numbers in the left and right hand segments.

**Puzzle 3: **Which number replaces the question mark?**Answer:**** 1**

**Explanation: **Working through the diagram in rows, the central value equals the sum of the other numbers in the row.

**Puzzle 4: **Which number replaces the question mark?**Answer: ****8**

**Explanation: **Multiply the 2 numbers in the outer segments together and add 1 to give the value in the inner segment opposite.

**Puzzle 5: **Which number replaces the question mark?**Answer: ****3**

**Explanation: **Split each grid into 2 halves, vertically, leaving 2 columns, each 2 squares wide. Start with the top left pair and move down, then to the top right pair, and down again. Reading each pair of digits as 2 digit values, the 2 digit values increase by 11, 12, 13, 14 and 15.