Explanation: \(\text{Hints: } \frac{V_1}{V_2} = \frac{\rho_2}{\rho_1}\) \(\text{Solve: } \frac{V_1}{V_2} = \frac{\rho_2}{\rho_1} \implies V_2 = \frac{\rho_1}{\rho_2}V_1 = \frac{1.025}{1.3} \times 0.9 = 0.71 = 71\%\) \([10\% \, \text{উপরে থাকলে } 90\% \, \text{ডুবে থাকে।} \implies V_1 = 90\% = 0.9]\) \(\therefore \text{পানির উপরে থাকলে } = (100 - 71)\% = 29\%\) \(\text{Ans. (C)}\)