If the plane \( P \) passes through the intersection of two mutually perpendicular planes \( 2x + ky - 5z = 1 \) and \( 3kx - ky + z = 5, \; k < 3 \) and intercepts a unit length on positive \( x \)-axis, then the intercept made by the plane \( P \) on the \( y \)-axis is:
