Q6 of 97 Page 786

On increasing the length of a rectangle by 20% and decreasing its breadth by 20%, what is the change in its area?

Let the length be l


And, breadth be b


Now,


Area = l × b = lb


Increase in length = 20% of length + length





Decrease in breadth = breadth - 20% of breadth






Since,



Therefore,


The area is decreased





= 4%


Hence change in area = 4% decrease

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