Question

A plastic box 1.5 m long, 1.25 m wide and 65 cm deep is to be made. It is opened at the
top
. Ignoring the thickness of the plastic sheet, determine:
( The area of the sheet required for making the box.
Ö) The cost of sheet for it, if a sheet measuring Im? costs * 20.​

Answer 1

Step-by-step explanation:

It is given that, length (l) of box = 1.5 m

Breadth (b) of box = 1.25 m

Depth (h) of box = 0.65 m

(i) Box is to be open at top.

Area of sheet required

= 2lh + 2bh + lb

= [2 × 1.5 × 0.65 + 2 × 1.25 × 0.65 + 1.5 × 1.25] m2

= (1.95 + 1.625 + 1.875) m2 = 5.45 m2

(ii) Cost of sheet per m2 area = Rs 20

Cost of sheet of 5.45 m2 area = Rs (5.45 × 20)

= Rs 109

m2is m square

Answer 2

Question :-

Plastic box 1.5 m long, 1.25 m wide and 65 cm deep is to be made. It is opened at the top. Ignoring the thickness of the plastic sheet, determine :-

(i) The area of the sheet required for making the box.

(ii) The cost of sheet for it, if a sheet measuring ${1m}^{2}$ costs ₹20.

given :-

• length (l) = 1.5 m,

• breadth(b) = 1 .25 m

• height (h) = 65 cm =$\dfrac{65}{100}$ m = 0.65 m

Solution :-

∵ It is open from the top.

∴ Its surface area

= [Lateral surface area] + [Base area]

= [2(1 + b)h] + [lb]

= [2(1.50 + 1.25)0.65] ${m}^{2}$ + [1.50 x 1.25] ${m}^{2}$

= [2 x 2.75 x 0.65] ${m}^{2}$ + [1.875] ${m}^{2}$

= 3.575 ${m}^{2}$+ 1.875${m}^{2}$ = 5.45 ${m}^{2}$

∴ Area of the sheet required for making the box

= 5.45 $\bold{ {m}^{2}}$

______________

ii) Cost of 1${m}^{2}$ sheet = Rs. 20

Cost of 5.45 ${m}^{2}$ sheet = Rs. (20 x 5.45)

= Rs. 109

Hence, cost of the required sheet = Rs. 109