Question

a cubical solid of metal has lenght,breadthand height as 40cm,30cm and 25 cm.If this solid is melted and recasted into solid cubes each of side 5 cm,find the number of cubes formed.

Answer 1

Length = 40 cm
Breadth = 30 cm
Height = 25 cm
Volume of the cuboidal metal solid = lbh
                                                   = 40 x 30 x 25
                                                   = 30000 cm^3

Volume obtained Cubical box by melting = 6a^3
                                                           = 6 x 5 x 5  x 5
                                                           = 750 cm^3

Number of cubes obtained = Initial volume / final volume
                                        = 30000/750
                                     Ans:  = 40 
Therefore number of cubes = 40.
Hope this helped you. And please confirm with ur teachers or any experts here if any wrong I have done. I think the sum is correct!. :-)

Answer 2

It is a cuboid with dimension
length = 40 cm
breadth = 30 cm
height = 25 cm
Volume(V)= lbh = 40×30×25 = 30000 cm³

Dimension of small cube obtained after recast is 5cm
volume(v) = a³ = 5³ = 125 cm³

Number of cubes= V/v = 30000/125 = 240
So total 240 cubes can be obtained.