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Example 8: What is the cost of ploughing a rectangular plot of land 500 m long and 300 m wide at
the rate of `8 per hundred sq. m?
Solution: Length of the rectangular plot = 500 m

Breadth of the rectangular plot = 300 m
Area of the rectangular plot = length × breadth = 500 m × 300 m = 1,50,000 sq. m
Cost of ploughing the rectangular plot of land at the rate of `8 per hundred sq. m
×
150000 8
= = ` 12 000
,
100
Example 9: A room is 4 m long and 2 m 50 cm wide. How many square metres of carpet is needed
to cover the floor of the room?

Solution: Length of the room = 4 m
Breadth of the room = 2 m 50 cm = 2.50 m
Area of the floor of the room = length × breadth = 4 m × 2.50 m = 10 sq. m

Hence, 10 sq. m of carpet is needed to cover the floor of the room.
Example 10: A floor is 6 m long and 5 m wide. A square carpet with sides of 4 m is laid on the floor.
Find the area of the floor that is not carpeted.
Solution: Area of the floor = length × breadth = 6 m × 5 m = 30 sq. m
Side of square carpet = 4 m

Area of square carpet = (side) = 4 m × 4 m = 16 sq. m
2
Hence, the area of floor which is not carpeted = 30 sq. m – 16 sq. m = 14 sq. m.
Example 11: Five square flower beds, each of sides of 2 m are dug on a piece 9 m
of land which is 9 m long and 6 m wide. What is the area of the remaining
part of the land? 2 m
2 m
Solution: Side of a square flower bed = 2 m 6 m
Area of a square flower bed = Side × side = 2 m × 2 m = 4 sq. m

So, the area of 5 square flower beds = 5 × (4 sq. m) = 20 sq. m
Length and breadth of a piece of land are 9 m and 6 m, respectively.
Area of the land = 9 m × 6 m = 54 sq. m

Hence, the area of the remaining part of the land = 54 sq. m – 20 sq. m = 34 sq. m.
Example 12: The perimeter of a square and a rectangle is same. If side of the square is 15 cm and
one side of the rectangle is 18 cm, find the area of the rectangle.
Solution: Side of a square = 15 cm

So, perimeter of the square = 4 × (side) = 4 × 15 cm = 60 cm
Given, perimeter of the square = perimeter of the rectangle
So, 60 cm = 2(length + breadth)
60 = 2(18 + breadth)

30 = 18 + breadth
breadth = 30 – 18 = 12 cm
Now, area of the rectangle = length × breadth = 18 cm × 12 cm = 216 sq. cm

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