Question

Three metal cubes with edges 6cm, 8 cm and 10 cm respectively melt down and form a single cube. Find the volume of the new cube. Also find the edge of the new cube with its total surface area.

Answer 1

volume remains same so
volume of new cube = v1+v2+v3
= 6^3+8^3+10^3
=216+512+1000
=1728
now volume of new cube = a^3= 1728

edge of new cube = a= cuberoot of 1728

a= 12

therefore surface area of new cube = 6 a^2
=6×12^2
=6×12×12
=864 square cm

Answer 2

Let volume of cubes be c1,c2,c3,

Then,