C188 His Answer Was too Clever

Mo Changyou immediately gave out eight answers. This question was indeed not difficult for him.

Now that fifteen minutes had passed, no one could think of an answer.

"Teacher, why didn't you answer? Since you already knew the answer, you should have said it first." Zi Tan was puzzled. He originally wanted to answer, but seeing that Mo Changyou did not seem to want to say anything