Let curved surface area of first cone is CS1. and curved surface area of second cone is CS2. As per the question, CS1=3CS2 ⇒πr1l1=3(πr2l2)⇒πr1l1=3πr2I2 ⇒r1l1=3r2I2⇒r1l1=3r2×3l1⇒r1l1=9r2l1 ∴r1=9r2 Now, required ratio of base area =‌