Let \( (\alpha, \beta, \gamma) \) be the image of the point \( P (2, 3, 5) \) in the plane \( 2x + y - 3z = 6 \). Then \( \alpha + \beta + \gamma \) is equal to:
\( 12 \)
\( 9 \)
\( 10 \)
\( 5 \)