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प्रश्न
A lawn is in the form of a rectangle whose sides are in the ratio 5 : 3. The area of the lawn is `3375m^2` . Find the cost of fencing the lawn at ₹ 65 per metre.
उत्तर
Let the length and breadth of the rectangular lawn be 5xmand3 xm, respectively.
Given:
Area of the rectangular lawn `3375m^2`
⇒`3375=5x xx 3x`
⇒`3375=15x^2`
⇒`3375/15=x^2`
⇒`225=x^2`
⇒ `x=15`
Thus, we have:
`l=5x=5xx15=75m`
`b=3x=3xx15=45 m`
Perimeter of the rectangular lawn =`2(l+b) `
=`2(75+45) `
=`2(120) `
=`240 m`
Cost of fencing 1 m lawn = Rs 65
∴ Cost of fencing 240 m lawn = `240xx65=Rs 15,600`
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