The Total solution for NCERT class 6-12
Let the edge of the cube = x cmIf the edge is doubled, then the new edge = 2x cm(i) Original surface area = 6x2 cm2New surface area = 6(2x)2 =6 × 4x2 =24x2Ratio = 6x2 :24x2 =1 : 4Hence, the new surface area will be four times the original surface area.
(ii) Original volume of the cube = x3 cm3New volume of the cube = (2x)3 =8x3 cm3Ratio = x3 :8x3 =1 : 8Hence, the new volume will be eight times the original volume.