Question

The outer dimensions of a closed wooden box are 10 cm*8 cm*7 cm. the thickness of the wood is 1 cm. find the total cost of wood required to make the box, if 1 cm^3 of wood costs rs.2

Answer 1

Solution :

Let Outer dimensions of a closed

box :

Length (L) = 10cm,

Breadth (B) = 8cm

Height(H) = 7cm

Thickness of the box (W) = 1cm

Inner dimensions of the box:

length (l) = L - 2W

= 10 - 2× 1 = 8cm

Breadth (b) = B - 2W

= 8 - 2 = 6 x

Height (h) = H - 2W

= 7 - 2 = 5cm

Now ,

Required wood to make the box

( V ) = LBH - lbh

= 10×8×7 - 8×6×5

= 560 - 240

= 320 cm³

It is given that ,

Cost of 1 cm³ wood = Rs 2

Cost of making the box = 320 × 2

= Rs 640

••••

Answer 2

Answer:

Rs 640

Step-by-step explanation:

Find the outer volume:

Volume = Length x Breadth x Height

Volume = 10 x 8 x 7 = 560 cm³

Find the inner volume:

Volume = Length x Breadth x Height

Volume = (10 - 2) x (8 -2 ) x  (7 - 2) = 240 cm³

Find the volume of the wood:

Volume = 560 - 240 = 320 cm³

Find the cost:

1  cm³  = Rs 2

320  cm³  = 2 x 320 = Rs 640

Answer: Rs 640