I get confused many times whether Dhritrashtra and Gandhari had 100 sons or just 99 sons with one daughter.
The 100th son was Yuyutsu who wasn't Gandhari's son but her maid's.
What's the truth? Were Kauravas 100 brothers or only 99?
There were 100 sons of Dhritarashtra. After 100 sons, Gandhari took out Duhshala, a baby girl, from the 101st jar.
You can read it here: http://samharshbangalore.blogspot.in/2012/10/101-children-of-dhritarashtra.html
Yuyutsu was son of Dhritarashtra but not from Gandhari. He was from Sughada, a woman from Vaishya Varna. He was born on the same day as Duryodhana.
In total Dhritarashtra had 102 children, 101 from Gandhari and 1 from Sughada.