Chapter 13 (2/2)

“Volume: 0.05 mL, Weight: 0.051 g, Speed: 8.52 m/s…”

“Volume: 0.06 mL, Weight: 0.059 g, Speed: 9.54 m/s…”

“Volume…”

Cheng Nuo lay in his bed and used the raindrops to test how many sets of statistics he was able to collect simultaneously.

And he had an answer: 100 sets.

At least that was what it seemed now.

Once this limit had been exceeded, Cheng Nuo would feel light-headed. Worrying that it might cause unforeseen problems, Cheng Nuo decided not to force his brain to collect more data.

To him, the ability to gather 100 sets of data concurrently was clearly sufficient.

…

The spring rain washed away the dust and dirt from the city streets. The next day, the air was teeming with the sweet smell of the fresh earth.

Cheng Nuo was summoned by Old Man Tang as soon as he reached the classroom.

“Cheng Nuo, Old Man Tang is looking for you again.” As usual, it was Qingqing who relayed the message.

When she said that, she shot Cheng Nuo a curious look. She wondered what he had done wrong that made Old Man Tang want to lecture him for two whole classes.

“Cheng Nuo. Come here.”

Once Cheng Nuo entered the office, Old Man Tang waved at him with a smile on his face.

Cheng Nuo hesitated.

He wasn’t used to Old Man Tang’s drastic change in attitude!

“Mr. Tang, are you looking for me?” It was the same old way Cheng Nuo would start a conversation with Old Man Tang.

“Come and take a look at this problem,” Old Man Tang said smilingly.

Cheng Nuo was feeling nervous…

“Can you solve this problem?” Old Man Tang asked. At that moment, Cheng Nuo was complaining silently.

“You could have passed me this problem last night! Why do you have to make me come to your office twice?”

Despite the grudge, Cheng Nuo started to read the problem.

“A plane contains n line segments, n≥2. Any segment crosses another one at one point, and no three segments cross at the same point. Geoff chooses an end point on every line segment and places a frog on the point with the frog facing the other end. Then Geoff claps n-1 times. Each time, the frogs jump to the next intersection point on their current segment. The frogs will not change the direction they jump in. Geoff hopes to place the frogs at the right points such that no two frogs will jump to the same intersection point at any point in time.

“(a) Prove that Geoff can always achieve his hope if n is odd.

(b) Prove that Geoff can never achieve his hope if n is even.”

Problems that even Old Man Tang considered challenging were meant to torture students.

Cheng Nuo had not had any ideas yet. Hence, he took a chair and started to solve the problem in front of Old Man Tang.

Meanwhile, Old Man Tang was paying close attention to Cheng Nuo’s actions.

In fact, it was completely unexpected to him that Cheng Nuo had been able to solve the problem the day before, so he hadn’t been focused on Cheng Nuo when he was doing the problem.

Now, however, he wanted to see whether Cheng Nuo had really become the genius that he had imagined.

While Cheng Nuo was scribbling on a piece of paper, Old Man Tang studied every step he wrote down closely to check if it made sense. At that moment, Old Man Tang looked like a student, looking at Cheng Nuo’s workings without even blinking.

Meanwhile, other math teachers came to the office too.

When they saw Old Man Tang staring at a student as the latter was solving problems, they couldn’t help but laugh. “Tang, what did this student do wrong again?”

They thought that the student had made a silly mistake in his work and Old Man Tang was teaching him how to solve the problem properly.

…