Question number 14. A water tank with a rectangular base has the dimensions 1 by 2 by 4 meters. It contains water to a depth of 25 cm as shown in the first picture. The tank is turned so that a 1 by 2 meter face becomes the base, as shown in the second picture. What is the depth of the water now? So, the first thing to notice is that the depth of the water in the first picture is 1 fourth of the total height, which is 25 cm divided by 1 meter is 1 fourth. And because of this, the volume of the water is also 1 fourth of the volume of the tank, because of course the water covers the entire base, and it has a depth of 1 fourth of the total height, and base times height is equal to volume. And this volume is also going to stay constant when the tank is turned, obviously. So, that means that the new depth also has to be 1 fourth of the new height, for this base times this height to be 1 fourth of this base times again this height, because the volumes are going to stay consistent no matter what. So, the new depth also has to be 1 fourth of the new height, and the new height over here is 4 meters, so 1 fourth of 4 meters is going to give us 1 meter, and with that the answer is D.

water tank

rectangular base

volume

depth

dimensions