the volume of the iron block put in is the same as the volume of the water rising, so the equation is listed with the volume as the equal relationship: suppose that the water surface will rise by Xdm.

4*4*4=7*6*X

if x is about 1, 52

, the water level will rise by 1,52 DM.

According to the topic, if the height of this rectangular water tank is 4dm, 2,8+1,52 = 4,32dm, the water will overflow.