​$$\text{A block of wood floats on water, with } 65\% \text{ of its volume under water. Its density (in } kg/m^3 \text{) is approximately:}$$​​

Correct option is D

​$$\text{We use the \textbf{principle of flotation}, which states that:} \\\text{Density of the object} = \text{Fraction of volume submerged} \times \text{Density of fluid} \\\textbf{Given Data:} \\\begin{array}{ll}\bullet \text{ Fraction of volume submerged} = 65\% = 0.65 \\\bullet \text{ Density of water} = 1000 \, \text{kg/m}^3\end{array} \\\textbf{Applying the formula:} \\\rho_{\text{wood}} = 0.65 \times 1000 \\\rho_{\text{wood}} = 650 \, \text{kg/m}^3 \\\text{Thus, the density of the wood is } 0.65 \times 10^3 \, \text{kg/m}^3.$$​​