If the area of a rectangular plot increases by 30%, and its breadth remains the same, what will be the ratio of the areas of new and old figures?

Correct option is B

Solution:

Let the initial area of the rectangular plot be denoted as A, and the initial length and breadth of the rectangle be denoted as L and B, respectively.
So, the initial area is given by:
​$$A = L \times B$$​​
When the area increases by 30%, the new area becomes 130% of the original area. Therefore, the new area, A', is:
​$$A' = 1.30 \times A$$​​​​​

$$\frac{A'}{A} = 1.30$$

$$\frac{A'}{A} = 1.30$$

Then A' : A = 13 : 10