u/FTfafa

This is Question #15 from the 2026 Korean CSAT (Suneung) Math section.

It had a 38.1% success rate, making it the 7th most difficult problem on the exam.

To get a perfect score, you'd have about 5 minutes to solve this.

Give it a shot!

This is a question from the 2026 Korea SAT (Suneung).

​To get a perfect score on this exam, you typically need to solve a problem of this difficulty level in about 2 to 3 minutes.

Also, remember that no calculators are allowed in the CSAT.

​Give it a try!

This is ranked 14th in difficulty among all math questions on the 2026 Korean College Entrance Exam (CSAT). Just a friendly reminder, calculators are not allowed for this exam. Good luck!