.@paultoo's "$100B question" challenges YC founders to think beyond their first $100M in revenue and envision what it would take to build a $100B company. YC Managing Partner @harjtaggar says the question reveals how much ambition and long-term vision founders in the batch really have. "Paul always had this great prompt which was, 'Don't just think about how you're going to be a $1B company with $100M in revenue. Think about the next act after that. How do you get to $100B? Google started off…