Volumes Practice Test 3

Let sides of the rectangular block are 3x, 2x and x dm respectively; then,
3x × 2x × x = 10368
⇒ ${\mathit{x}}^3$ = $\frac{10368}{6}$ = ${\left(12\right)}^3$
∴ x = 12
Since, three sides are 36, 24 and 12 dm respectively;
Hence, total surface area = 2(36 × 24 + 24 × 12 + 12 × 36)
= 2(864 + 288 + 432)
= 2 × 1584 = 3168 $\mathit{d}{\mathit{m}}^2$ Hence, total cost of polishing = Re. $\frac{2}{100}\times 31628$ = Rs. 63.36