A.) See attachment for diagram. Amounts from left to right, top to bottom are: 500mm, 460mm, S.G.=0.8, S.G.=1.05, 300mm, 300mm and Tank X is water.
Calculate difference in pressure between centers of tank X and Y.
B.) See attachment for diagram again. Amounts are: Pa=2.7kPa, 0.05m, 20mm, S.G.(Oil)=0.6, S.G.=1.4, 30mm, 10mm.
Find the distance d for the U tube.
The fluid of SG=0.8 has column = 500 mm in left hand side limb
and in right hand side it's height = (500+460) - (300+300) = 360 mm
SG of water = 1.0
When we go up in a fluid of given SG by a height h, the pressure decreases by = (SG*1000)*9.8*h
And when we come down, the pressure ...
The solution shows each step in the calculation of the difference in pressures in two water tanks as well as the distance of a U-tube working fro diagrams provided from the asker.