VTMO 2026 - Grade 3 - Semifinal - SET 10 - Self-study Question 18

Tiến and Sơn start with the same amount of money. Tiến buys 3 pencils and 4 notebooks and has 7 dollars left. Sơn buys 3 pencils and 3 notebooks and has 28 dollars left. How many dollars does one notebook cost?