Question

The area of a rectangular field is $12k{m}^2$. If the width is four less than its length, then the width of this rectangular tray is .

• A. 2 km
• B. 3 km
• C. 4 km
• D. 6 km

Answer 1

The correct option is A 2 km

Let the length of the rectangular field be $x$ km.
Then its breadth will be $(x-4)$ km.
We know that,
Area of rectangle = length$\times$breadth
$⟹12=x(x-4)$
$⟹x^2-4x=12$
$⟹x^2-4x-12=0$
$⟹x^2+2x-6x-12=0$
$⟹x(x+2)-6(x+2)=0$
$⟹(x+2)(x-6)=0$
$⟹x+2=0$ or $x-6=0$
$⟹x=-2$ or $x=6$
We reject $x=-2$ as the dimension cannot be negative.
Hence, $x=6$
$⟹x-4=6-4=2$
$\therefore$ The width(breadth) of the rectangular field is 2 km.