Q.The curved surface area of a right circular cone is \(\sqrt{10}\) times the area of its base. What is the ratio of the height of the cone to the diameter of its base?

Let the height of the cone be \(h\), slant height be \(l\), and radius be \(r\) units. \(\therefore \pi rl = \sqrt{10} \times \pi r^2\) i.e., \(l = \sqrt{10}r\) Again, \(h = \sqrt{l^2 - r^2}\) \(= \sqrt{(\sqrt{10}r)^2 - r^2}\) \(= \sqrt{10r^2 - r^2}\) \(= \sqrt{9r^2} = 3r\) \(\therefore h : 2r = 3r : 2r = 3 : 2\)
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