Determining Students' Favorite Fruit

A survey was conducted among 200 students to determine their favorite fruit. The results showed that 40% of the students preferred apples, 25% preferred bananas, 20% preferred oranges, and the remaining students preferred grapes.

If the students who preferred grapes were surveyed again and 10% of them indicated that they would like to add strawberries to their list of favorites, how many students initially preferred grapes?