Question

6. A poster of size 10 cm by 8 cm is pasted on a sheet of cardboard such that there is a margin of
width 1.75 cm along each side of the poster.
Find the total area of the margin (ii)the cost of the card-board used at the rate of Rs1.80/sqcm.​

Answer 1

Answer:

l = 10 cm

b = 8cm

L = 10+1.75 =11.75

B = 8+ 1.75 = 9.75

area of margin = total area - area of poster

= 11.75*9.75 - 10*8

= 114.5625 - 80

= 34.5625 sq cm

rate of cardboard = 0.60 per sq cm

cost of cardboad = total area * rate

= 114.5625* 0.60

= 68.737500 rs

Step-by-step explanation:

Answer 2

Given -

• Length of poster = 10cm

• Breadth of Poster = 8cm

• Margin of width = 1.75cm

• Rate of cardboard used = 1.80cm²

To find -

• Total area of Margin and cost.

Formula used -

Area of rectangle = L × B

Solution -

First we will find the area of the Poster, by using the formula of area of rectangle.

Area of poster = L × B

where,

L = Length

B = Breadth

On substituting the values -

$\longmapsto$ Area = L × B

$\longmapsto$ Area = 10cm × 8cm

$\longmapsto$ Area = 80cm

Now,

We will find the length and breadth of the cardboard by using the length and breadth of the poster and we will also add the margin two times in it.

Length of cardboard = length of poster + margin

Breadth of cardboard = Breadth of poster + margin.

On substituting the values -

$\longmapsto$ Length of cardboard = 10cm + 1.75cm + 1.75cm

$\longmapsto$ Length of cardboard = 13.5cm

Similarly,

$\longmapsto$Breadth of cardboard = 8cm + 1.75cm + 1.75cm

$\longmapsto$ Breadth of cardboard 11.5cm

Now,

We will find the area of cardboard by using the formula of area of rectangle.

Area of cardboard = L × B

where,

L = Length

B = Breadth

On substituting the values -

$\longmapsto$ Area = L × B

$\longmapsto$ Area = 13.5cm × 11.5cm

$\longmapsto$ Area = 155.25cm

Similarly -

Now we will find the area of the margin, for that we will subract the area of cardboard from the area of poster.

Area of Margin = area of cardboard - area of poster.

On substituting the values -

$\longmapsto$ Area = 155.25cm - 80 cm

$\longmapsto$ Area = 75.25cm

At the end -

Cost of cardboard used = Rate given × area of cardboard.

$\longmapsto$ Cost of cardboard = ₹1.80 × 155.25

$\longmapsto$ ₹275.45

$\therefore$ Area of margin is 75.25cm and cost is ₹275.45

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