Rishu saves x% of her income. If her income increases by 26% and the expenditure increases by 20%. then her savings increase by 50%. What is the value of x?

\[\begin{array}{*{20}{c}} {{\text{Income}}}&{{\text{Saving}}}&{{\text{Expenditure}}} \\ { \Rightarrow 100}&x&{100 - x} \\ { \Rightarrow 126}&{1.5x}&{120 - 1.2x} \end{array}\]
$$\eqalign{ & {\text{Now, Income }} - {\text{ Saving}} = {\text{Expenditure}} \cr & 126 - 1.5x = 120 - 1.2x \cr & 6 = 0.3x \cr & x = 20 \cr} $$