Assignment Difficulty

[Bad Karma]

An elementary school teacher decides to pole the class on the difficulty of last night's homework assignment:
How many people were able to complete the assignment without parents help?
About 25% of the class raises their hands. How many people we able to complete the assignment with the help of a parent? About 70% of the class raises their hand. The teacher still notices about 5% of the class did not raise their hands.

She then calls out, "How many people had to help a parent complete your assignment?