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प्रश्न
The length of a rectangular field exceeds its breadth by 8 m and the area of the field is `240 m^2` . The breadth of the field is
(a) 20 m (b) 30 m (c) 12 m (d) 16 m
उत्तर
Let the breadth of the rectangular field be x m.
Length of the rectangular field =`(x+8)m`
Area of the rectangular field=`240m^2` (Given)
∴` (x+8)xx x=240` `"(Area"="Length" xx "Breadth)"`
⇒` x^2+8x-240=0`
⇒`x^2+20x-12x-240=0`
⇒`x(x-20)-12(x+20)=0`
⇒`(x+20)(x-20)=0`
⇒`x+20=0 or x-12=0`
⇒`x=-20 or x=12`
∴ x=12 (Breadth cannot be negative) Thus, the breadth of the field is 12 m Hence, the correct answer is option C.
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