Question

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 Im costs Rs 20​

Answer 1

Answer:

1. 5.45 meters square

2.109 rupees

Step-by-step explanation:

1. first, we have to acknowledge the fact that we are not calculating the top, as it is an open box. then, lets get on with it. lets start with the bottom. the length is 1.5m and and the width is 1.25m, so for the bottom of the box, we have to multiply those two together. then, we get 1.875.

lets now do the two shorter sides. since they are the shorter sides, we us the width given to us, which is 1.25. we multiply it by the depth, 65cm, remember, this is a mistake i always make, so i will tell you about it. its 65 cm, not metres, so when we're multiplying it, we should use it as convert it to metres, so we should get 0.65. anyways, the answer for this part is 0.8125. there are two of these, so we multiply by 2, to get 1.625.

last part, longer side, this time 0.65 * 1.5, giving us  0.975, times 2, giving us 1.95.

add all of these together, you get you answer, 5.45 meters square.

2. just multiple by 20, as it says every 1m, so super easy, giving us 109 rupees

Answer 2

$\large{\underline{\rm{\orange{\bf{Question:-}}}}}$

A plastic box 1.5 m long, 1.25 m wide and 65 cm deep, is to be made. It is to be open 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 1 m² costs Rs. 20.

$\large{\underline{\rm{\orange{\bf{Given:-}}}}}$

Length of the box = 1.5 m

Width of the box = 1.25 m

Depth of the box = 65 cm

$\large{\underline{\rm{\orange{\bf{To \: Find:-}}}}}$

The area of the sheet required for making the box.

The cost of sheet for it, if a sheet measuring 1 m² costs Rs. 20.

$\large{\underline{\rm{\orange{\bf{Solution:-}}}}}$

Given that,

Length of the box (l) = 1.5 m

Width of the box (b) = 1.25 m

Depth of the box (h) = 65 cm

Figure:

$\setlength{\unitlength}{6}\begin{picture}(10,6) \put(0,1){\line(0,1){10}}\put(0,1){\line(1,0){10}}\put(10,1){\line(0,1){10}}\put(0,11){\line(1,0){10}}\put(0,11){\line(1,1){5}}\put(10,11){\line(1,1){5}}\put(10,1){\line(1,1){5}}\put(0,1){\line(1,1){5}}\put(5,6){\line(1,0){10}}\put(5,6){\line(0,1){10}}\put(5,16){\line(1,0){10}}\put(15,6){\line(0,1){10}}\put(2, - 0.5){ \bf 1.5 m }\put(13,3){ \bf 1.25 m }\put( - 5, 5){ \bf 0.65 m }\end{picture}$

Solution I:

Box is to be open at top.

$= \boxed{\sf 2lh + 2bh+lb}$

$\sf =[2 \times 1.5 \times 0.65 \times 2 \times 1.25 \times 0.65 +1.5 \times 1.25] \: m^{2}$

$\sf = (1.95+1.625+1.875) \: m^{2} = \underline{\underline{5.45 \: m^{2}}}$

Therefore the 5.45 m² of sheet is required for making a box.

Solution II:

Cost of sheet per m² area = Rs.20

Cost of sheet of 5.45 ²m area = $\sf Rs. \: (5.45 \times 20)$

$\sf = \underline{\underline{Rs. \: 109}}$

Therefore it costs Rs. 109 if per m² is Rs. 20.