Li Zheng, caught up in his emotions, was suddenly startled by two loud thumps on the table—one on the left and one on the right—as two notebooks were slapped down.
The quiet nerdy guy and the cool, aloof big sister both lugged their chairs and sat down on either side of the table.
"I stored the first problem in my calculator," the nerdy guy said as he started scribbling on the paper at a rapid pace, "I'll handle problems two and three."
"I'll take four, five, and six," the big sister spoke while tearing off two pieces of paper and sliding them to Li Zheng, "Don't just sit there, tackle problems seven to ten, write down as much as you can remember."
Li Zheng suddenly realized, they were cross-checking the answers.
This task, without the support of scratch paper or the original exam, was extremely difficult.
It had to be done purely from memory.
And in the half hour just after the exam, when memories were most intact, indeed, there was no time to waste.