Question

Three cubes of metal whose edges are 9, 12 and 15 cm respectively, are melted and one new cube is made. find the edge of the new cube?

Answer 1

vol. of the first cube = 9^3 = 729
vol. of the second cube = 12^3 = 1728
vol. of the first cube = 15^3 = 3375
therefore total vol. = 729+1728+3375 =5832.
therefore vol. of the newly formed cube = 5832
so, edge of the new cube = 5832^(1/3) = 18.

Answer 2

Given:

Edges of three cubes are 9, 12, and 15 cm

To find:

The edge of the new cube

Solution:

Volume of the first cube = 9^3

                                         = 729

Volume of the second cube = 12^3

                                        = 1728

Volume of the third cube = 15^3

                                 = 3375

The Total volume = 729 + 1728 + 3375

                             =5832

The volume of the new cube = 5832

The edge of the new cube = $\sqrt[3]{5832}$

                                            = 18cm

Hence, the edge of the new cube is 18cm.