surface integrals orientation. when is it positive or negative

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For this question below, I don't understand what they're asking. what does it mean to find the net flow rate upward through the surface? How do I know if I need to put a negative before computing the surface integral? Also, I've only encountered questions where they ask about the net flow out of the surface ( positive orientation ) and the net flow inside the surface ( negative orientation). but here, they ask for an upward net flow, which seems ambiguous. like does that mean the normal is pointing outward or inward? In brief, im just not sure how to figure out when is the orientation positive or negative enter image description here.