*Even though the title says "Daily", I won't be doing them daily any more, until the exams get closer. But they will be frequent.*

### Geometry, August 2015, Question 25

**25. ** *A wooden cube has an edge length of 6 centimeters and a mass of 137.8 grams. Determine the density of the cube, to the nearest thousandth.
State which type of wood the cube is made of, using the density table below.*

Density is defined as Mass divided by Volume. (d = m/V). You are given the length of one edge of a cube. The volume of the rectangular prism = length times width times height (V = L * W * H). However, with a cube, all three values are the same, so V = s^{3}.

Density = mass / Volume. Volume of a cube = (edge length)^{3}.

If you substitute the values that we know, we find that Density = mass / (edge)^{3} = 137.8 / (6)^{3} = 0.63796..., which rounds to 0.638.

According to the table, the approximate value of **Ash** wood is 0.638.

The wood is Ash.

Note: Don't forget to identify the wood after finding the density, even if you just circle the correct answer.

Also: If you get "Ash" without showing any work, you will NOT score a point.

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