Question

A closed box is cuboid in shape with length = 40 cm, breadth = 30 cm and height = 50 cm. It is made of thin metal sheet. Find the cost of metal sheet required to make 20 such boxes, if 1 m2 of metal sheet costs Rs. 45.

Answer 1

Length of closed box (l) = 40 cm

Breadth (b) = 30 cm

and height (h) = 50 cm

Total surface area = 2 (lb + bh + hl)

= 2 (40 x 30 + 30 x 50 + 50 x 40) cm2

= 2 (1200 + 1500 + 2000) cm2

= 2 x 4700 = 9400 cm2

Surface area of sheet used for 20 such boxes = 9400 x 20 = 188000 cm2

Cost of 1 m2 sheet = Rs. 45

Total come = (1800x45/100x100x100)

= Rs.846