Solve the following ques

Question

The inner dimensions of a closed wooden box are 2m by 1.2m by 0.75m. The thickness of the wood is 2.5cm. Find the cost of wood required to make the box if 1m3 of wood costs Rs. 5400

Answer 1

Given

Inner dimensions of wooden box are 2 m by 1.2 m by 0.75 m

Thickness of the wood = 2.5 cm = 2.5/100 m = 0.025 m

Now

External dimensions of wooden box are

= (2 + 2 x 0.025) by (1.2 + 2 x 0.025) by (0.75 + 2 x 0.025)

= (2+0.05) by (1.2+0.05) by (0.75+0.5)

= 2.05 by 1.25 by 0.80

Thus

Volume of solid = External volume of box - Internal volume of box

= 2.05 x 1.25 x 0.80 m³ − 2 x 1.2 x 0.75 m³

= 2.05 − 1.80 = 0.25 m³

Given, the cost of wood = Rs 5400 for 1 m³

Hence, Total cost = Rs 5400 x 0.25 = Rs 5400 x 25/100 = Rs 54 x 25

= Rs 1350