Question

18. Three cubes of metal with edges 3 cm, 4 cm and 5 cm respectively are
melted to form a single cube. The lateral surface area of the new cube
formed is
(a) 72 cm? (b) 144 cm? (c) 128 cm?
(d) 256 cm?

Answer 1

Answer:

144 cm

Step-by-step explanation:

cubes with edge 5,3,4 volume of a cube will be =(5x5x5),(4x4x4), (3x3x3)

= 1256427 total volume will be 125+64+27=216 this volume will be of new formed

cube =4x(6x6) =4x36 =144

side of cube =cube root of volume = 6

lateral surface area of cube is

4x(sidexside)