1.  A large cube is formed from the material obtained by melting three smaller cubes of 3, 4 and 5 cm side. What is the ratio of the total surface areas of the smaller cubes and the large cube? 

Answer: Option C Explanation: Volume of the large cube = (3^{3} + 4^{3} + 5^{3}) = 216 cm^{3}. Let the edge of the large cube be a. So, a^{3} = 216 a = 6 cm.
