MYTS 2019 — Grade 5 — Round 1 Question 11

A pen shop offers these promotions: buy 4 pens, get 1 free; buy 6 pens, get 2 free and receive 1000 đồng back. What is the least amount of money needed to obtain exactly 38 pens? Each pen costs 2000 đồng. Give the answer in đồng.