How many rational solutions for $x$ are there to the equation $x^4+(2-p)x^3+(2-2p)x^2+(1-2p)x-p=0$ if $p$ is a prime number?
To determine the number of rational solutions for the equation 

\[ x^4 + (2 - p)x^3 + (2 - 2p)x^2 + (1 - 2p)x - p = 0 \]

where \( p \) is a prime number, we can use the Rational Root Theorem. The Rational Root Theorem states that any rational solution, expressed as a fraction \(\frac{p}{q}\), must have \( p \) as a factor of the constant term and \( q \) as a factor of the leading coefficient.

1. **Identify the constant term and the leading coefficient:**
   - The constant term is \(-p\).
   - The leading coefficient is \(1\).

2. **List the possible rational roots:**
   - The factors of the constant term \(-p\) are \(\pm 1, \pm p\).
   - The factors of the leading coefficient \(1\) are \(\pm 1\).
   - Therefore, the possible rational roots are \(\pm 1, \pm p\).

3. **Test the possible rational roots:**
   - We need to check if \( x = 1, -1, p, -p \) are solutions to the polynomial equation.

4. **Check \( x = 1 \):**
   \[
   1^4 + (2 - p)1^3 + (2 - 2p)1^2 + (1 - 2p)1 - p = 1 + (2 - p) + (2 - 2p) + (1 - 2p) - p
   \]
   \[
   = 1 + 2 - p + 2 - 2p + 1 - 2p - p = 4 - 6p
   \]
   Since \( 4 - 6p \neq 0 \) for any prime \( p \), \( x = 1 \) is not a solution.

5. **Check \( x = -1 \):**
   \[
   (-1)^4 + (2 - p)(-1)^3 + (2 - 2p)(-1)^2 + (1 - 2p)(-1) - p = 1 - (2 - p) + (2 - 2p) - (1 - 2p) - p
   \]
   \[
   = 1 - 2 + p + 2 - 2p - 1 + 2p - p = 0
   \]
   Therefore, \( x = -1 \) is a solution.

6. **Check \( x = p \):**
   \[
   p^4 + (2 - p)p^3 + (2 - 2p)p^2 + (1 - 2p)p - p = p^4 + 2p^3 - p^4 + 2p^2 - 2p^3 + p - 2p^2 - p
   \]
   \[
   = p^4 - p^4 + 2p^3 - 2p^3 + 2p^2 - 2p^2 + p - p = 0
   \]
   Therefore, \( x = p \) is a solution.

7. **Check \( x = -p \):**
   \[
   (-p)^4 + (2 - p)(-p)^3 + (2 - 2p)(-p)^2 + (1 - 2p)(-p) - p = p^4 - (2 - p)p^3 + (2 - 2p)p^2 - (1 - 2p)p - p
   \]
   \[
   = p^4 - 2p^3 + p^4 + 2p^2 - 2p^3 - p + 2p^2 - p
   \]
   \[
   = p^4 - p^4 - 2p^3 + 2p^3 + 2p^2 - 2p^2 - p + p = 0
   \]
   Therefore, \( x = -p \) is a solution.

Since we have found that \( x = -1 \) and \( x = p \) are solutions, we conclude that there are two rational solutions.

The final answer is \(\boxed{2}\).