A cube of ice floats partly in water and partly in kerosene oil. The ratio of volume immersed in water to that in kerosene oil is:
Step 1: {Define variables}
Let \( V_1 \) be the volume immersed in water and \( V_2 \) be the volume immersed in oil.
Step 2: {Equilibrium condition}
\[ V_1 \rho_w g + V_2 \rho_o g = (V_1 + V_2) \rho_{{ice}} g \]
Step 3: {Solve for ratio}
\[ V_1 + 0.8 V_2 = 0.9 (V_1 + V_2) \] \[ 0.1 V_1 = 0.1 V_2 \Rightarrow V_1 : V_2 = 1:1 \] Thus, the correct answer is 1:1.