Page 225 - New Medley 5 Semester 1

The widths of the two paths are 3 m and 4 m respectively.

So, area of the crossing in the centre

= 3 m × 4 m = 12 sq. m

and area of the paths

= (48 × 3 + 48 × 4 – 12) sq. m

= (144 + 192 – 12) sq. m = 324 sq. m

Thus, area of the remaining field

= 2304 sq. m – 324 sq. m

= 1980 sq. m

Example 7: There is a park 140 m long and 100 m wide. A 5 m wide

road is to be constructed around its boundary. If the cost
of constructing the road is `2000 per sq m, find the amount

of money needed to construct it.

Solution: This rough sketch shows the shape of the park and the
road to be constructed.

Length of the park = 140 m and breadth = 100 m

 Area of the park = 140 m × 100 m = 14000 sq. m

Now, length of the park
140 + 2 × 5 m
including the road = (140 + 5 5 m

+ 5) m = 150 m and breadth of
the park including the road =

(100 + 5 + 5) m = 110 m 100 + 2 × 5 m 100 m Park 5 m

Now, Area of the park with
road = 150 × 110 sq. m = 140 m

16500 sq. m

Thus, area of the road = 16500 – 14000 = 2500 sq. m

Hence, the required amount for the road at the rate of `2000

per sq. m = `(2500 × 2000) = `50,00,000

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