I don't understand why there's so much confusion. All you need to do is understand the question, and get rid of the red herring information. Who cares that the flight is VFR, or what the elevation was at an airfield you left some time ago?
What it boils down to is this:
You are at an eleveation of 300'. The QNH is 998mb. The altimeter sub-scale is set to 1020mb. What does the altimeter read
As others have said, (1020-998) * 30 = 660', so you will over-read by 660'. Answer: 960'. The prize goes to Dufwer.
FFF
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