Difference between number and problem in Korean
번호·문제
번호number
The word "number" means a numeral or a set of digits used to identify something. In Korean, 번호 often means a phone number, seat number, bus number, or student number. You use it when you ask for or tell the number of something in everyday life. At school, it can also mean your class number or student number.
문제problem
문제 means a problem. In school, it often means a question or exercise in a workbook, homework, or a test. You can also use it for a difficulty in daily life, like a problem with a computer or a ticket.
The difference
번호 is a number, like a student number, phone number, or the number of a test item. It does not mean the question or problem itself.