Find the percent of decrease.

Original rent: $600

New rent: $450

600 - 450 = 150

150 / 600 = 0.25 = 25%

To find the percent of decrease between the original rent and the new rent, you can use the following formula:

Percent of decrease = ((original rent - new rent) / original rent) x 100

In this case, the original rent is $600 and the new rent is $450.

Using the formula:

Percent of decrease = (($600 - $450) / $600) x 100
= ($150 / $600) x 100
= 0.25 x 100
= 25%

Therefore, the percent of decrease is 25%.