Absolute Pressure Question Confusion

[betterfuture]

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Let p be the total pressure at depth d below the surface of a large body of water, and let P be the total pressure at depth 2d. Assuming that the variation in density is negligible, how do P and p compare?

A) P<2p
B) P=2p
C) P>2p
D) Cannot be determined without knowing d

Someone explain this to me please. I am getting conflicting answers.

 

[theonlytycrane]

Total pressure = Psurface + Pgauge where Pgauge = density (of the fluid) * depth * gravity.

p = Psurface + density * d * g

P = Psurface + density * 2d * g

Because of the added Psurface term, P is bigger than p, but is less than double p. So P < 2p.

 

[betterfuture]

That's what I thought. However, answer says its P<2p.

 

[theonlytycrane]

See above. It's because of the added Psurface term.

 

[betterfuture]

Ahh. Got it! Thanks!