A man spends 75% of his income. If his income rises by 20% and expenses by 10%, his savings rise by:

1. Let income = 100. Savings = 25 (since 75 is spent). 2. New income = 120. New expenses = 75 * 1.10 = 82.5. 3. New savings = 120 - 82.5 = 37.5. 4. Increase in savings = 37.5 - 25 = 12.5. 5. Percent increase = (12.5 / 25) * 100 = 50%. 6. So savings rise by 50%. _Source: SSC CGL Quantitative Aptitude (Percentages), R.S. Aggarwal style and standard practice_