A man spends 75% of his income. His income increases by 20% and his expenditure also increases by 10%. Find the percentage increase in his savings.

let the income = Rs 100 expenditure = 75% of his income = 75% of 100 = Rs 75 savings = 100 - 75 = 25 (savings = income − expenditure) income increases by 20% new income = 100 + (20/100) × 100 = 100 +20 = Rs 120 new expenditure = 75 + (10/100) × 75 = 75 + 7.5 = Rs 82.5 new savings = 120 - 82.5 = 37.5 increase in savings = new savings - initial savings = 37.5 - 25 = Rs 12.5 % increase in savings =(increase in savings / initial savings) × 100 = (12.5/25) × 100 = 50%