其它
Cindy and Chloe are siblings. Each of them have $$2$$ brothers and $$2$$ sister in. How many children are there in the family? 
Overseas Competition->Knowledge Point->Combinatorics->Logical Reasoning
Cindy is sister to Chloe and Chloe is sister to Cindy. Thus, they have one more common sister. There are a total of $$3$$ girls in the family.  Their brother are the same, thus $$2$$ boys in the family.  In total $$5$$ children. 