Question

20) three cubes of edges 6 cm, 8 cm and 10 cm are meted without loss of metal into a single cube. The edge of the new cube will be: a) 16 cm b) 14 cm c) 12 cm d) 8 cm

Answer 1

The sum of the volume of the 3 cubes being melted will be the volume of the new cube formed.

Volume of the cube is the cube of the length of its edge.

So the total volume of the 3 cubes would be 6^3 + 8^3 + 10^3 which is 216 + 512 + 1000 = 1728 which happens to be the cube of 12.

So the edge of the new cube would be 12 cm.