If the ratio of the volumes of two spheres is 8:27, find the ratio of their surface areas.

आयतन अनुपात (R₁³/R₂³) = 8/27 => त्रिज्या अनुपात (R₁/R₂) = 2/3। पृष्ठीय क्षेत्रफल अनुपात = R₁²/R₂² = 2²/3² = 4/9।