The sum of the ages of $4$ children, Anu, Benu, Chris and Dave is $20$.  Dave is $5$ years older than Chris, and $3$ years older than Benu.  Anu is $3$ years younger than Chris. How old is Anu 
Overseas Competition->Knowledge Point->Word Problem Modules->Age Problems->Basic Relationships in Age Problems->Basic Sum and Differences Problems in Age Problems