Question

a plastic box 1.5m long 1.25m wide and 65cm deep is to be made. it is opened at the top ignoring the thickness of the plastic sheet, determine.
1) the area of the sheet required for making the box
2) the cost of sheet for it a sheet measuring 1m square cost rupees 20.​

Answer 1

Answer:

dimensions-l=1.5m,w=1.25 h=65cm

We convert l and w in cm 100cm=1m

l=150,w=125,h=65cm

the box opened at top,the top is lb

area of cuboid= 2lb+2bh+2hl

now are of box =lb+2bh+2hl

because there is no top

area of box=150×125+2×125×65+65×150

=54500cm square

the cost of sheet for it a sheet measuring 1m square= Rs 20

now we convert the area into m

1m square=10000

54500/10000=5.45m square

now,we multiple 20from 5.45 to find the cost of sheet

5.45×20=109

109 is the cost of sheet

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 ❤