Question

A plastic box 1.5m long,1.25wide and 65cm 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 square cost Rs 20.​

Answer 1

Step-by-step explanation:

Refer to this attachment

Answer 2

${ \huge{ \bold{ \underline{★ Given:}}}}$

A plastic box of dimensions 1.5m x 1.25m x 65cm that is open at the top.

${ \huge{ \bold{ \underline{★ To \: Find:}}}}$

The area of the sheet required making the box.

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

${ \huge{ \bold{ \underline{★ Solution:}}}}$

➽First of all, we can take 65 cm as 0.65 m.

➠Part 1)

➽The area of the sheet required making the box = 2 (lh + bh) + lb

[It is because the box is open at the top]

• Length = 1.5 m
• Breadth = 1.25 m
• Height = 0.65 m

→ Substituting the values in the formula:

= 2 [(1.5 x 0.65) + (1.25 x 0.65)] + (1.5 x 1.25)

= 2 [0.975 + 0.8125] + 1.875

= [2 x 1.7875] + 1.875

= 3.575 + 1.875

= 5.45 m²

The area of the sheet required is 5.45 m².

➠Part 2)

Cost of 1 m² sheet = Rs 20.

So, cost of 5.45 m² sheet = 5.45 x 20

= Rs. 109

Hence the total cost of sheet is Rs. 109.

${ \huge{ \bold{ \underline{★Final \: answer}}}}$

The area of sheet required is 5.45 m².

Total cost of sheet is Rs 109.