Question

Three cubes of silver with edges 3cm,4cm and 5cm are melted and recarted into single cube find the cost of coating the surface of new cube with gold at rate 2.7 per square cm​

Answer 1

S1 = 3 cm

S2 = 4 cm

S3 = 5 cm

v of cube = s³

V1 = 3³ = 27 cm³

V2 = 4³ = 64 cm³

V3 = 5³ = 125 cm³

total volume = 27+64+125 = 216 cm³

V4 = 216 cm³

S4³ = 216

S4 = ³√216 = 6 cm

TSA of cube = 6s²

TSA = 6 × 6²

= 6 × 36 = 216 cm²

cost of gold plating = 216 × 2.7 = ₹583.2

therefore the cost of covering the new cube with gold will be ₹583.2