Katrina's twins, Sheri and Meri, finished their first year of college during the tax year. She paid $10,000 in educational expenses for Sheri at the local accredited university, which includes $6,000 in tuition and fees, $750 in textbooks and required course materials, and $2,250 in room and board. She also paid $4,000 of qualifying expenses for Meri at the local accredited community college, which includes $3,200 in tuition and fees, as well as $800 in textbooks. Katrina is single with an AGI of $91,000. 

What amount of qualified education expenses can Katrina claim for the American opportunity credit?