The reason he said those words earlier is because he was certain that Hao Jian definitely couldn't solve this problem. After all, how could any first-year high school student solve a question from a Level 6 English exam, especially when this student sleeps through classes? Could someone who doesn't even listen in class figure it out?
Even with divine intervention or the protection of Bodhisattvas, it's unlikely that he could solve this. Under such circumstances, he confidently believed that Hao Jian had no chance of solving this problem, no matter from which angle he contemplated it.
However, contrary to his expectations, the outcome was completely unexpected—Hao Jian actually solved the problem.
Moreover, he did it effortlessly, without even thinking, and wrote down the answer on the blackboard. His arteries were practically twisted with regret for having said those words earlier.
