Given a 60 uC point charge located at the origin find the to

Given a 60 uC point charge located at the origin, find the total electric flux passing through the plane at z=26 cm

(The book shows the answer as 30 uC).

Solution

Since electric flux lines from a point charge emanate in every possible direction, only a quarter of these should be passing through the plane which is \"above\" the point charge. So the flux should be 15-C.Half the total electric flux parallel to the given line.
But There will be effectively none perfectly parallel to the plane. Even the slightest deviation from parallel will mean that the line either passes through the plane or gets ever further from it.

so answer is 30uC