A man saves a certain part of his monthly income so that he can purchase a bike in 30 months. Find the percent increase in his savings so that he can purchase the same bike in 24 months only.

25%

Let the cost of bike = Rs.120

Now,

To purchase the bike in 30 months, savings should be = \(\frac{120}{30}\) = 4 Rs./mnt

To purchase the bike in 24 months, savings should be = \(\frac{120}{24}\) = 5 Rs./mnt

Increase in savings = 5 - 4 = 1 Rs./mnth

Saving increase percentage = \(\frac{1}{4}\) × 100% = 25%