VTMO 2026 - Grade 4 - Final - SET 3 - Self-study Question 5

A stationery shop offers these pencil prices: 1 pencil for 3 000 đồng, 2 pencils for 5 000 đồng, and 5 pencils for 9 000 đồng. What is the greatest number of pencils Pi can buy with 53 000 đồng?