If the length of a rectangle is increased by 12% and the breadth is decreased by 8%, the net effect on the area is:

Let the length of the rectangle = $$l$$

Breadth of the rectangle = $$b$$

Area of the rectangle = $$lb$$

Length of the rectangle when increased by 12% = $$\frac{112}{100}l = \frac{28}{25}l$$

Breadth of the rectangle when decreased by 8% = $$\frac{92}{100}b=\frac{23}{25}b$$

New Area of the rectangle = $$\frac{28}{25}l\times\frac{23}{25}b=\frac{644}{625}lb$$

$$\therefore\ $$Percentage increase in Area = $$\frac{\frac{644}{625}lb-lb}{lb}\times100=\frac{19}{625}\times100=3.04\%$$

Hence, the correct answer is Option B