The volume of the cube of unknown substance is
. The length of one side of the cube is 9 cm
<u>Explanation:</u>
As per the formula of mass and density, Mass / Density equals to volume. Therefore as the mass of the cube was given to be 81 g and the density of the cube is known to be 3.0 g/
,, to help Bill find out the volume. It is the ratio of mass and density and can be calculated as

As it is a cube, the volume is product of length, breadth, and height. Here, all sides are same as it is the cube.



Lactose because it is a sugar made up of galactose and glucose.
<h3><u>Benefits of smooth stem over rough stem:</u></h3>
Smooth stem plants like guava, eucalyptus etc do have a smooth layer of bark over its stem that comes out as a skin when they shed their barks. Whereas most of the other plants like mango, banyan etc do have a rough corrugated layer of bark over their stem.
The smooth stem doesn’t let water to accumulate in the bark which can led to infections to the tree. It also doesn’t allow any seed to settle on bark that can led to growth of parasites. Thereby this smooth bark saves the trees from some of the probable harm to the tree.