The mat foundation in the figure below is 45 m wide and 90 m long. Bottom of the foundation is located at 15m below the ground surface. It has a weight of 140 MN. The sum of the applied structural loads is 1300 MN. Compute the average bearing pressure with the groundwater table at position A (located 21m below the ground surface). Then repeat the computation with the groundwater table at position B (located 6.5m below the ground surface). Explain why these two values of q are different