• # question_answer The diameters of two cones are equal. If their slant height be in the ratio $5:7$, find the ratio of their curved surface areas. A)  $25:7$                        B)  $25:49$       C)  $5:49$           D)  $5:7$

(d): Let the radius of the two cones be = ?x? cm Let slant height of 1st cone = 5y And, Slant height of 2nd cone = 7y Then, the ratio of curved surface area $=\frac{\pi x.5y}{\pi x.7y}=5:7$