ANSWER IS $25\mathrm{.}5\%$ POROSITY. I need help with the steps. Given that the weight of dry sample of limestone in air is $20\mathrm{.}0g,$ weight of pycnometer filled with mercury at $20C$ is $350\mathrm{.}0g$ and weight of pycnometer filled with mercury and sample at $20C$ is $235\mathrm{.}9g(($:${}_{\text{m}\text{e}\text{r}\text{c}\text{u}\text{r}\text{y}}=13\mathrm{.}546\frac{g}{c}c\}.$ Determine the sample bulk volume and porosity.

Calculate the initial oil$-$in