Let Jack’s original salary be Rs 100. Then,
his expenditure = Rs 75,
his savings = Rs 25.
Now, his new salary = Rs 120. So,
new expenditure = (110/100) × 75 = Rs 165/2,
new savings = 120 – 165/2 = Rs 75/2.
Increase in savings = 75/2 – 25 = Rs 25/2.
Therefore, percentage increase in savings = (25/2)/25 × 100% = 50%.
