A man spends 75% of his income. This income is increased by 20% and he increased his expenditure by 10%. His savings are increased by?

Let income = Rs. 100
Then expenditure = Rs. 75 and saving = Rs. 25
New expenditure = 110% of Rs. 75 = Rs. 165 / 2
New saving = Rs. (120 - 165/2) = Rs. 75/2
Increase in saving = Rs. (75/2 - 25) = Rs. 25/2
∴ Increase% = (25/2) x (1/25) x 100% = 50%