Three metal cubes whose edges measure 3cm, 4cm and Scm respectively are melted to form a single cube, find its :
Answer: (3) 6 cm
The edge of first cube = 3 cm
Then, volume of first cube (V1 ) = 3^3 = 3 x 3 x 3
= 27 cm^3
The of second cube = 4 cm
Then, volume of second cube(V2) = 4^3 = 4 x 4 x 4
= 64 cm^3
The edge of third cube = 5 cm
Then, volume of third cube(V3) = 5^3 = 5 x 5 x 5
= 125 cm^3
After melting, volume of the ‘single’ new cube is V cm3.
Let the edge of the new cube be x cm.
The sum of the volume of the three cubes before melting = Volume of the new cube formed after melting
V1 + V2 + V3 = V
27 + 64 + 125 = (x)3
x3 = 216 x = 3 = 6 cm
The required edge (of the new cube) is 6 cm.
Hence, the correct answer is option (3) 6 cm