In 1736， Euler founded Graph Theory by solving the Konigsberg seven-bridge problem. It has been more than two hundred years till now. Graph Theory is the core content of Discrete Mathematics， and Discrete Mathematics is the theoretical basis of Computer Science and Network Information Science. This book vulgarly introduces in an elementary way some basic knowledge and the primary methods in Graph Theory. Through some interesting mathematic problems and games the authors expand the knowledge of Middle School Students and improve their skills in analyzing problems and solving problems.

《世界数学奥林匹克经典》由数学竞赛命题委员会主席和数学邀请赛命题委员会主席等专家共同编著。《世界数学奥林匹克经典》自出版后就深受广大使用者的好评。《世界数学奥林匹克经典》为英文版本。

Probability theory is an important branch of mathematics， with wide applications in many fields. It is not only a required course for students of science and technology at universities， but also has entered into Chinese high school textbooks now.This little book will， in an interesting problem-solving way， explain what probability theory is： its concepts， methods and meanings; particularly， two important concepts-probability and mathematical expectation （briefly expectation）-are emphasized. It consists of 65 problems， appended by 107 exercises and their answers.As an extracurricular book providing supplement materials to and advanced knowledge beyond high school textbooks， its aim is to stimulate study interests of students and broaden their knowledge horizons. Some problems were given a little deeper treatment， which can be used as topics for explorative study; and they can also be skipped temporarily if a reader feels difficult to understand them at the beginning.It is presupposed that our readers possess a knowledge of permutations and combinations， and it would be better if they have already learned basic probability theory from their textbooks. However， in order to avoid repetition， we mention as little as possible the contents of textbooks.It is a random event that this little book reaches you. I do not know how much the probability that this event occurs is. However， it is my expectation that this book could reach you， which means that you have a special affinity with it.

《世界数学奥林匹克经典》由数学竞赛命题委员会主席和数学邀请赛命题委员会主席等专家共同编著。《世界数学奥林匹克经典》自出版后就深受广大使用者的好评。《世界数学奥林匹克经典》为英文版本。

This book consists of three parts： fundamental knowledge， basic methods and typical problems. These three parts introduce the fundamental knowledge of solving combinatorial problems， the important solutions to combinatorial problems and some typical problems with often-used solutions in the high school mathematical competition respectively.In each chapter there are necessary examples and exercises with solutions. These examples and exercises are of the same level of difficulty as the China Mathematical League Competitions which are selected from mathematical competitions at home and abroad in recent years. Some test questions are created by the author himself and a few easy questions in China Mathematical Olympiad （CMO） and IMO are also included. In this book， the author pay attention to leading readers to explore， analyze and summarize the ideas and methods of solving combinatorial problems. The readers' mathematical concepts and abilities will be improved remarkably after acquiring knowledge from this book.

Number theory is an important research field in mathematics. In mathematical competition， problems of elementary number theoryoccur frequently. This kind of problems uses little knowledge and has lots of variations. They are flexible and diverse.In the book we introduce some basic concepts and methods in elementary number theory via problems in mathematics competition.We hope that readers read the book with paper and pencil， and try to solve them by themselves before they read the solutions of examples.Only in this way can they really appreciate the tricks of problem solving.

Mathematical induction is an important method used to prove particular math statements and is widely applicable in different branches of mathematics， among which it is most frequently used in sequences.This book is rewritten on the basis of the book Methods and Techniques for Proving by Mathematical Induction ， and is written with an understanding that sequences and mathematical induction overlap and share similar ideas in the realm of mathematics knowledge. Since there are a lot of theses and books related to this topic already， the author spent quite a lot of time reviewing and refining the contents in order to avoid regurgitating information. For example， this book refers to some of the most updated Math Olympiad problems from different countries， places emphasis on the methods and techniques for dealing with problems， and discusses the connotations and the essence of mathematical induction in different contexts.The author attempts to use some common characteristics of sequences and mathematical induction to fundamentally connect Math Olympiad problems to particular branches of mathematics. In doing so. the author hopes to reveal the beauty and joy involved with math exploration and at the same time， attempts to arouse readers' interest of learning math and invigorate their courage to challenge themselves with difficult problems.

全书按照《高等数学》教学大纲的基本要求进行编写。本书为满足基础课教学的需要，以巩固学生的基础知识、强化数学的理解能力、提高数学的应用能力为目标，由烟台大学的一线教师组织编写。作者具有深厚的数学专业功底和丰富教学经验。本书内容包含极限与连续，导数与微分、中值定理、不定积分、定积分、定积分的应用等部分的习题及解答，并附有两套模拟试题。本书可作为高等院校非数学专业学生的习题册，也可作为学生自学的参考书。

本书是“新时代大学数学系列教材”《概率论与数理统计》的配套参考书，由教材主编编写。本书按照主教材章节顺序，归纳了概率论与数理统计课程的主要知识点，主要内容包括教材各章的重要知识点、详细习题解答，并结合考研复习要点对历年考研题进行了分析。本书的习题解答注重体现数学思想，有助于读者加深对学科知识的理解。本书可作为高等学校非数学类专业本科生概率论与数理统计课程的参考书，可供考研复习使用，也可供对概率论与数理统计感兴趣的读者参考。

本书内容包括概率论的基本概念和方法， 数理统计的点估计、区间估计、参数和非参数假设检验以及线性回归等内容。本书的特点是突出统计思想， 对基本概念和方法都有如何理解、应用的阐述和例子，例子和习题大部分来自于实际生活，有助于读者把统计方法用于实际数据的处理和解读。每章后都有大量的习题供读者练习以巩固相关的概念，还提供了开阔读者视野的扩展阅读材料。重点概念和方法配备了视频讲解和在线模拟实验。本书可以作为理工科专业概率论与数理统计课程的教材， 也可以供金融工程、大数据、生物统计等业内工程技术人员和科学研究人员参考。