**Puzzle-1: **Which letter replaces the question mark?**Answer: ****Z**

**Explanation: **Start on the top left of the diagram, and move from left to right, top row to bottom row. Letters advance through the alphabet in steps of 6, 7 then 8, before repeating this pattern.

**Puzzle-2: **Which letter replaces the question mark?**Answer:**** Q**

**Explanation: **Starting on the top left, and moving around the whole diagram in an anti- clockwise direction, outside then inside, letters advance through the alphabet 5 letters at a time.

**Puzzle-3: **Which letter replaces the question mark?**Answer: ****G**

**Explanation: **Start at the top of the triangle and move anti-clockwise around it. Letters move through the alphabet in steps of 3, 4, 5, 6 etc.

**Puzzle-4: **Which letter replaces the question mark?**Answer: ****Y**

**Explanation: **Starting with the G and moving clockwise, letters advance through the alphabet in steps of 3 letters, then 4, then 5 etc.

**Puzzle-5: **Which letter replaces the question mark?**Answer: ****V**

**Explanation:**** **Starting on the top left of each outer square, and moving clockwise around the corners of the squares, letters advance through the alphabet in steps of 4 for the upper left square, 5 for the upper right, 6 for the lower right and 7 for the lower left. Additionally, the letters bounded by the central square take the inverse alphabetical value of the original letter.