To find the percent decrease of Max's movie collection, we need to find the difference between his original collection and his new collection, divide that by his original collection, and then multiply by 100 to express the answer as a percentage.
The difference between his original collection and his new collection is:
1,000 - 750 = 250
So the percent decrease is:
(250 / 1000) x 100% = 25%
Therefore, Max's movie collection decreased by 25%.