Two cubes each of volume $125 cm^3$ are joined end to end. The surface area of the resulting solid is

$250 cm^2$

Volume of cube = (side)³

(side)³ = 125

(side)³ = (5)³

side = 5 cm

Total length of side of new cube = 5 + 5 = 10 cm

breadth = 5

height = 5

Surface area of resulting cuboid = 2 ( lh + bh + hl )

= 2 ( 10 × 5 + 5 × 5 + 5 × 10 )

= 2 ( 50 + 25 + 50 )

= 2 ( 125 )

= 250

The correct answer is Option (2) → $250 cm^2$