Question

1. A plastic box 1.5,
top. Ignoring the th
(1) The area of
EXERCISE 13.1
15 mlong, 1.25 m wide and o3 cm deep is to be made. It is opened at the
noring the thickness of the plastic sheet, determine:
The area of the sheet required for making the box
The cost of sheet for it, if a sheet measuring Im costs Rs 20
baadth and height of
​

Answer 1

using formula length × breadth × height

Answer 2

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

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

(ii) The cost of sheet for it, if a sheet measuring 1m2 costs ₹20.

Answer :-

(i) Here, length (l) = 1.5 m, bread th(b) = 1 .25 m

and height (h) = 65 cm = 65/100 m = 0.65 m

∵ 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] m2 + [1.50 x 1.25] m2

= [2 x 2.75 x 0.65] m2 + [1.875] m2

= 3.575 m2+ 1.875 m2 = 5.45 m2

∴ Area of the sheet required for making the box = 5.45 m2

(ii) Cost of 1 m2 sheet = Rs. 20

Cost of 5.45 m2 sheet = Rs. (20 x 5.45)

= Rs. 109

Hence, cost of the required sheet = Rs. 109

Plz mrk as brainliest ❤