1. 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.
(i) The cost of sheet for it, if a sheet measuring 1m² costs Rs 20.
cost of white washing the walls of the room and the ceiling at the rate of
EXERCISE 13.1
2
7.50 per m2
Answers
Answer:
I am giving answer in PDF but please follow me
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 ❤