A man saves a certain part of his monthly income so that he can purchase a bike in 18 months. Find the percent increase in his savings so that he can purchase the same bike in 12 months only.

50%

Let the cost of bike = Rs.72

Now,

To purchase the bike in 18 months, savings should be = \(\frac{72}{18}\) = 4 Rs./mnt

To purchase the bike in 12 months, savings should be = \(\frac{72}{12}\) = 6 Rs./mnt

Increase in savings = 6 - 4 = 2 Rs./mnth

Saving increase percentage = \(\frac{2}{4}\) × 100% = 50%