Objective Questions (MCQ)

Let the breadth of the rectangular field be x m.

∴ Length of the rectangular field = (x + 8) m

Area of the rectangular field = 240 m2

$\therefore(x+8) \times x=240 \quad$ (Area = Length $\times$ Breadth)

$\Rightarrow x^{2}+8 x-240=0$

$\Rightarrow x^{2}+20 x-12 x-240=0$

$\Rightarrow x(x+20)-12(x+20)=0$

$\Rightarrow(x+20)(x-12)=0$

$\Rightarrow x+20=0$ or $x-12=0$

$\Rightarrow x=-20$ 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.