Police in the Mekong Delta said Wednesday they arrested a college student as he was selling fake university entrance exam answers to parents waiting outside a college.

Dinh Thanh Liem, a 20-year-old at Tay Do University in Can Tho, was hawking the answer sheets to parents waiting for their children at the Can Tho Junior College exam council, city police said.

Liem reportedly admitted to investigators he downloaded last year’s answer key and altered their date before distributing them for VND3,000 (14 U.S. cents) per copy. He sold roughly 50 in all.

At the junior college, students were taking the math portion of a two-day national college admission test that ended Thursday.

Vietnam requires all college-bound students to take the exam, which alone determines which school will accept them.