To solve this problem, we need to determine the value of x, which represents the percentage increase in the number of pieces for the second and third puzzles compared to the first puzzle.
Let's break down the information given:
Number of pieces in the first puzzle: 1000
Number of pieces in the second and third puzzles: x% more than the first puzzle
Total number of pieces in all three puzzles: 4000
We can set up the equation as follows:
Number of pieces in the first puzzle + Number of pieces in the second puzzle + Number of pieces in the third puzzle = Total number of pieces
1000 + (1000 + (x/100)*1000) + (1000 + (x/100)*1000) = 4000
Let's simplify and solve for x:
1000 + (1000 + 10x) + (1000 + 10x) = 4000
3000 + 20x = 4000
To isolate x, we subtract 3000 from both sides of the equation:
3000 + 20x - 3000 = 4000 - 3000
20x = 1000
To solve for x, we divide both sides of the equation by 20:
x = 1000 / 20
x = 50
The value of x is 50.
#### 50
The answer is: 50
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
John buys 3 puzzles.  The first puzzle has 1000 pieces.  The second and third puzzles have the same number of pieces and each has x% more pieces. All the puzzles have 4000 total pieces. What is the value of unknown variable x?

### Answer:
