A majority of Suneung test takers viewed this year’s College Scholastic Ability Test or Suneung as being difficult overall, rekindling doubts that the government was able to tackle "killer questions."

A poll on 2,764 students conducted by the Educational Broadcasting System showed Friday that a combined 85.9 percent found this year's Suneung either "extremely difficult" or "moderately difficult."

This came after test takers who took the state-administered college entrance exam on Thursday found some questions to be as difficult as the so-called “killer questions.”

The most controversial question is question number 22 in the mathematics section. This was a question to infer the type of graph that satisfies the condition by considering the sign of the differential coefficient. Based on this, a functional equation should be obtained.

A slew of test takers expressed frustration with posts on the online community Orbi.

“I still don’t know how to solve it,” one unnamed test taker wrote online on Friday. Also, an instance of a mathematics instructor at a private hagwon spending more than 20 minutes to solve the question went viral online.

Regarding the controversy, the Ministry of Education said, "Although the question is challenging, it does not require the problem-solving skills (that are only) taught in private education.”

Sim Joo-seok, a math teacher at Incheon Haneul High School, said in a news briefing Thursday at the Government Complex Sejong, “This question was a question of distinguishing between the highest and the high-ranked students. But it was not at the level of killer questions students gave up trying to solve (because they did not know how to solve them) like in the past.”

Earlier in June, the Education Ministry announced that it would exclude “killer questions” or excessively difficult questions where their material is not covered in the school's ordinary education system, soon after President Yoon Suk Yeol revealed that the killer questions allow the assessment authorities and private education sector altogether to profit by exclusively providing students with strategies to solve them.

The underlying logic of the announcement was that students and parents had been forced to spend too much money on private hagwons and tutoring largely because the exams include things that are not taught in the public school curriculum -- known as killer questions.

A total of 504,588 examinees flocked on Thursday to 1,279 test sites in 84 cities, counties and districts nationwide to sit the nine-hour five-session exam, according to the education ministry.