The quadratic equation is \( x^2 - 5x + 6 = 0 \). We know from Vieta's formulas that for a quadratic equation \( ax^2 + bx + c = 0 \), the sum of the roots \( p + q \) is given by \( -\frac{b}{a} \).
For the equation \( x^2 - 5x + 6 = 0 \), we have \( a = 1 \), \( b = -5 \), and \( c = 6 \). Therefore:
\[
p + q = -\frac{-5}{1} = 5
\]
Thus, the value of \( p + q \) is 5. Therefore, the correct answer is option (1).