Just as Lynn expected, the high demands didn't deter Lydia. Instead, it ignited her spirit, and she earnestly examined the design plans.
Upon learning that crafting an airship required lightweight yet durable materials, Lydia immediately suggested using water-soaked and sun-dried camel-hide leather for the airship's envelope. This material was well-suited to the task and was commonly used in the sails of large warships. The ship they sailed on in the Misty Sea had sails made of camel-hide leather, which withstood even the fiercest storms, proving to be highly durable and reliable.
As for the frame of the airship, they could use branches from the magical oak tree, known for its high tensile, compressive, and bending strength...
Lydia talked passionately about the subject, admitting that while she couldn't match Lynn's expertise in designing flying machines, she had a deep understanding of the unique properties of materials in this foreign world.
Lynn quietly calculated the cost in his mind. If they followed Lydia's suggestions for materials, the airship's performance would undoubtedly improve, but the cost would skyrocket. It would cost at least a hundred magic gold coins.
Considering his limited savings, Lynn couldn't help but clear his throat and interrupt Lydia's speech. "Actually, this airship is just a prototype. We don't need the best materials for it. Something more budget-friendly should do."
Lydia protested, "How can that be? This is the first airship capable of turning in the sky."
Lynn, somewhat helpless, took out a coin pouch and continued, "I can offer you twelve magic gold coins as an advance payment."
Lydia shook her head, refusing to accept the coins. She pointed out that the knowledge Lynn had shared during the lecture was worth far more than a hundred magic gold coins. Moreover, the success of this airship project was crucial for her admission to the Iyeta Academy.
"The money for making the airship can be considered as the tuition for your recent lesson. I'll use the best materials to build it, starting now." Lydia wiped dirt off her face, instructed Darren to call the other halflings from the workshop, and declared her intention to finish building the airship within a month.
Observing the busy halflings, Lynn wanted to lend a hand but was stopped. Using magic could leave traces, and if the airship was suspected of being magically constructed, it could lead to problems. Besides, Lynn was a customer, and there was no reason for a customer to work himself.
With nothing else to do, Lynn could only stand by, offering guidance while watching the halflings, who were half his height, carry heavy wooden materials.
***
The progress of the airship's construction was faster than Lynn had imagined. After a night of hard work, they had completed one-sixth of the overall framework. If it weren't for the time-consuming special treatment required for the camel-hide leather used in making the envelope, the airship might have been finished within a month.
However, such rapid progress came at a cost. The halflings were nearly exhausted, and the enthusiasm they had shown earlier had been channelled into their work. Darren was snoring away on a sturdy board, and Lydia had gone a step further, sleeping on the airship's frame, clutching a beam tightly, with drool at the corner of her mouth and mumbling in her sleep.
Lynn shook his head, halted the halflings who were still prepared to work, and moved Lydia and the others, who had fallen into a deep slumber, indoors to rest.
After becoming a wizard apprentice, staying up all night had no effect on Lynn's mental state. So, after settling the exhausted Lydia, he left the workshop.
A whole day had passed, and Lynn was somewhat eager to see if the wizard apprentices had been able to solve the mathematical problems he had left for them.
Pushing the classroom door open, Lynn found a substantial pile of coins on the lectern, significantly more than he had expected. What surprised him even more was that the classroom, which had felt somewhat empty during the previous lesson, was now packed to the brim with students. If the room weren't large enough, it might have been overcrowded.
Was a math puzzle game really this popular?
"Good morning, everyone," Lynn thought, his mind racing, though his demeanor remained unchanged.
However, the students' responses were even more enthusiastic than he had imagined.
"Professor Lynn, do you have more math problems for us?"
"I've already solved the puzzles with thirty-six squares and forty-nine squares..."
The students' excitement about the mathematical puzzles was beyond Lynn's expectations.
Looking at the ecstatic wizard apprentices in the classroom, Lynn was utterly shocked. Were all the students at the Iyeta Academy secretly a bunch of masochists? They seemed to have an incredible enthusiasm for solving math problems.
But something must have happened that he wasn't aware of. Lynn decided not to rush to confirm and turned to Elok, inquiring, "It's been a day now. I believe you should have the answers, right, Elok?"
"Professor, the sum of the 34,359,738,368..." Elok hastily stood up, trembling as he gave his answer.
He had double and triple-checked the value, calculating it on twenty different sheets of paper. The final figure was just too large, and he only had one chance to answer. A single mistake would be disastrous.
Under Elok's anxious gaze, Lynn nodded. "Very good, correct answer."
"Have you also figured out the meaning of the formulas I gave you?" Lynn inquired further.
"I've figured it out. The sum of the numbers in the squares is equivalent to twice the last digit." Elok confidently responded. After spending a sleepless night to find the correct answer, his confidence was back.
Lynn nodded once more, acknowledging Elok's achievement. Given his limited mathematical background and only a day to work with, discovering this pattern was quite commendable.
"Professor Lynn, can I get my reward now?" Elok asked eagerly.
Pierce and others gazed at Elok with envy. Twenty magic gold coins was no small sum. While they had also struggled with the problem for a long time, they hadn't worked as hard as Elok or managed to find the pattern first.
Lynn, aware of the reward set by Master Herlram for the formula, knew that he couldn't take it himself due to his position.
But claiming the money based on this simplistic pattern was too far-fetched.
"Elok, my summation formula is not that simple. Let me ask you, if I were to slightly modify the rules of the square game, like requiring the number in the next square to be three times that of the previous one, would your theory still apply?" Lynn asked with a sly grin.
Elok's smug expression froze as he immediately began calculating in his mind. He then picked up a quill and started scribbling on parchment.
"What if I added a rule where you need to place seventeen copper coins in the first square?" Lynn continued.
Elok was completely bewildered, his mind overwhelmed with a massive amount of numbers. This was just too challenging.
He couldn't figure it out at all.