If field lines come out from a closed surface treat them as positive. If field lines go in to a closed surface treat them as negative.

Two concentric spherical surfaces are drawn around a positive point charge Q so that the charge is at the center of each surface. Surface A has a radius of R, while surface B has a radius of 2R. Which surface has more field lines passing through it?

Make some observations about the number of field lines passing through the surface in different situations.

How does the number of field lines passing through a surface relate to the charge enclosed by the surface?

You should have concluded that the net number of field lines passing through a closed surface is proportional to the charge enclosed by the surface. This is the essence of Gauss' Law.