There was nothing important about Huo Yanran's work on Xia Yu, but it was just a meal appointment between normal best friends. They had no time to meet each other for a while. Unexpectedly, after Xia Yu finished the exam, he brought Yang Yan and Luoluo with him.

"How are you doing in the exam?" Huo Yanran teased her for a while, and finally turned her head and asked with concern.

"It's okay, I finished all the questions in the morning, and then the afternoon interview. I don't know the rating criteria for the examiner." Xia Yu put down the cup of drinking water and replied.

"How are you answering the math questions in the practical test? Are you sure?" Yang Yan hadn't asked Xia Yu these questions yet. At noon, he was worried that it would affect Xia Yu's interview status in the afternoon, so he didn't mention it a word, but he was still concerned about this question because according to the past civil service examinations he collected, the math questions will be the key to scoring!

"I basically did it all, but fortunately you told me those quick calculations and other techniques!" Xia Yu looked at Yang Yan gratefully, and then fell into the memory of hard work. "However, there is a question I was confused about. The question is: 10 consecutive... odd numbers, no, even numbers, and the sum of even numbers is the sum of 10 consecutive odd numbers starting with 1... 2.5 times, it asks what the largest even number is."

When Xia Yu reviewed with Yang Yan, all the average value, arrangement and probability issues were involved, but Xia Yu remembered that Yang Yan had never told her the problem of odd numbers or even numbers. As a result, when she saw this question during the exam, she was a little confused.

"At the beginning, I calculated it directly, 1, 3, 5, 7, 9... I forgot to use the arranging sequence, but later I was worried that I didn't have enough time, so I was obsessed with an option a, because I thought that the number in the middle was more average, and 2.5 times of 9 was only 22.5. To the largest even number, it should be around 34.5, and 34 is closer." Xia Yu rushed to tell Yang Yan how he solved this problem. After saying that, she still looked at Yang Yan eagerly, wanting Yang Yan to tell her that she was not wrong.

Although it was just a selection exam, once Xia Yu made up her mind to take the exam, she really spent a lot of effort and energy to review, so Xia Yu felt it was very important for every point.

However, after hearing the answer she said, Yang Yan smiled and said, "I found that you are becoming more and more mathematical now!"

Xia Yu had already vaguely felt that he might have been right, but Yang Yan had not given a positive answer, which made her a little crazy.

"Tell me quickly! Alas, when is it time to keep me in silence here?" Xia Yu was anxious and couldn't help but stomp his feet under the table.

"I mean you're right! Moreover, you're also right in solving the problem with the intermediate value!" Yang Yan brought a napkin on the table, then took out the pen for Xia Yu's exam from his bag, and wrote the formula with her, "This question is actually an equation of arranging sequence!"

"From 1, 10 consecutive odd numbers, the sum of them is: (1+1+9x2) divided by 2. Let's not care about the result, let's look at the sum of the other ten consecutive even numbers first. Similarly, the sum formula of its sum is also. Wait a minute, let's assume that the first even number is x, then this formula is (x+x+9x2) and then divided by 2!" Yang Yan wrote on the tissue, Xia Yu, the three good student, also put his head close and listened intently.

What are mom and dad doing?

Luoluo, who was sitting on the other side with her aunt, couldn't see what her father was writing. Of course, she couldn't understand the "complex" formulas her father said, but she couldn't help but curiosity, and she stood up on the sofa, and took two little hands to the dining table.

"Be careful, don't climb up!" Huo Yanran hurriedly hugged Luo Luo's weak waist, carried her back, let her little butt sit in her arms, and said softly, "You can't move around in this public place, do you know? Especially when climbing onto the table, it's not okay, because it's impolite!"

Luo Luo still had a strong interest in what her father and mother did. She hummed and stretched out her little hand, and did not listen to what her aunt said.

Let’s not talk about Luoluo for now, Yang Yan’s solution to the problem is very clear and fast. He quickly crossed out the same terms in the two formulas, such as dividing by 2, and multiplying by 2 in brackets, and the same number (symbol). In the end, only (1+9) and (x+9) are left, and the interval between them is multiplied by 2.5!

"Here, you see the odd number in front, the remaining one is 10. It is actually about the same middle number you mentioned, but in fact, there should be 9 and 11 in the middle of 10 odd numbers, and their average number should be 10." Yang Yan smiled and said, "But it doesn't matter, because the results are all the same. The x we ​​found here is 16, and when the fourth number is 22, it is almost the same, which is almost the same as the 22.5 you mentioned."

Therefore, although Xia Yu is a quick algorithm for blindly confusing, she actually concealed the right direction, so she also calculated the correct value!

Of course, Yang Yan did forget it quickly, and his thoughts were very clear to Xia Yu, but Xia Yu was unable to get out of these formulas at once. She picked up the napkin written by Yang Yan and was still watching carefully.

Huo Yanran couldn't stand it anymore, and she complained: "After the exam, why are you looking at? No matter how you do the questions? Yang Yan, you said so much, I only remember one sentence, Xia Yu got the question right!"

"Hurry up, order food, order food!" Huo Yanran called the waiter to bring the menu. At this time, Xia Yu put down the tissue.

Huo Yanran ignored Yang Yan and Xia Yu, a serious couple who loves to be "sharp". She spread the menu in front of Luoluo and asked with a smile: "Luoluo, look, what do you like to eat? Are you good to order food?"

The colorful menu, relying on the beautiful food photos, attracted Luo Luo's attention. The little girl didn't bother to explore what her father and mother were studying, and she looked at the menu with great enthusiasm.

However, Western restaurants, especially this is a very high-end Western restaurant, have many dishes on the menu, and they also have separate dishes, soups, side dishes, etc.! Huo Yanran flipped through several pages, and Luoluo couldn't finish it.

"Um..." The little girl couldn't help it, and her fleshy little palm pressed on the menu, otherwise the aunt would turn the page.

People haven't finished watching it yet!

"Why, do you want to order this French baked onion soup?" Huo Yanran asked with a funny look. She was actually making fun of Luoluo, and she didn't see that Luoluo had a very obvious intention for this dish.

However, what surprised Huo Yanran was that the little girl raised her head and looked at herself. She quickly pursed her mouth and nodded while making a dull "um" sound.

"Okay, then what else do you want?" Huo Yanran looked at the little guy with interest.

What do you want?

Luoluo wants so much!

I saw Luo Luo return to the menu with many beautiful colorful photos. She pressed her hands on it, sweeping one by one, her little mouth pouting, and said in a slight voice: "Add it, arrogance, arrogance..."

"Then, don't want any of these?" Huo Yanran thought of a joke and couldn't help laughing.
Chapter completed!