To find the density of the rock, you can use the formula:
\[ \text{Density} = \frac{\text{Mass}}{\text{Volume}} \]
Given:
- Mass = 13.5 grams
- Volume = 5 mL
Now, substitute the values into the formula:
\[ \text{Density} = \frac{13.5 \text{ grams}}{5 \text{ mL}} = 2.7 \text{ g/mL} \]
Therefore, the density of the rock is 2.7 g/mL.