The width of a rectangular hall is ½ of its length. If the area of the hall is 800 sq.m, what is the difference between its length and breadth?  Choose the correct choice from the following answers.
A) 8m B) 10m C) 12m D) 20m E) 17m
Let the length of the hall be x m   Breadth of the hall = 1x/2 m   Area of the hall = Length * Breadth   800 = x * 1x/2   x² = 1600   x =40   20mifference between the length and breadth of the hall = x - 1x/2 = x/2   =40/2= 
<gadget id="calculator">40/2</gadget>
<output>20</output>
20m   ANSWER:20m
<result>D</result>
The width of a rectangular hall is ½ of its length. If the area of the hall is 800 sq.m, what is the difference between its length and breadth?