An elementary school teacher decides to poll the class on the difficulty of last night’s homework assignment. The question was: "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?"