Let the income be Rs.100
Amout spent = 75% = Rs.75
Therefore, savings = Rs.25
new income = \( 100 + \left(100 \times \frac{20}{100}\right) \)
new expenditure = 10% increase
(i.e) \( \Large 75 + \left(75 \times \frac{10}{100}\right) \) = 82.5%
Therefore, new savings = Rs.120 - Rs.82.5 = Rs.37.5
Therefore, increase percent in savings = \( \Large \left(\frac{37.5-25}{25} \times 100\right) \)=50%