A larger cube is formed from the material obtained by melting three s…

Question

A larger cube is formed from the material obtained by melting three smaller cubes of 3, 4 and 5 cm side. The ratio of the total surface areas of the smaller cubes and the larger cube is :

Accepted Answer

Option C. 25 : 18. Answer & Solution Answer: Option C Solution: Volume of the larger cube : & = ( 3^3 + 4^3 + 5^3 ) c m^3 & = 216 c m^3 Let the edge of the larger cube be a cm & a^3 = 216 & a = 6 Required ratio : & = 6 ( 3^2 + 4^2 + 5^2 )6 × 6^2 & = 6 × 506 × 36 & = 2518\,Or\,25:18