The Heart of Mathematics: An Invitation to Effective Thinking
4th Edition
ISBN: 9781118156599
Author: Edward B. Burger, Michael Starbird
Publisher: Wiley, John & Sons, Incorporated
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 2.1, Problem 15MS
The last one. Here is a game to be played with natural numbers. You start with any number. If the number is even, you divide it by 2. If the number is odd, you triple it (multiply it by 3), and then add 1. Now you repeat the process with this new number. Keep going. You win (and stop) if you get to 1. For example, if we start with 17, we would have:
Play four rounds of this game starting with the numbers 19, 11, 22, and 30. Do you think you will always win no matter what number you start with? No one knows the answer!
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
With six card, each card has 32 numbers on it. If Fraudini added two new cards (and updated the old ones) so that he could "read" your mind for larger number
What numbers would appear in the upper left-hand corners of the new cards? Explain.
What would be the largest number that he could "read" (it was 63 for six cards)? Explain .
Which of his eight cards would have the number 213 on them? Explain.
Tristan tried his luck with the lottery. He can win $50 if he can correctly choose the 3 numbers drawn. If order matters and there are 12 numbers in the drawing, how many different ways could the winning numbers be drawn?
You and your 3 roommates gave out a lot of candy on Halloween, but you still have
34 pieces of candy left.
How many different ways can you divide up the remaining 34 pieces of candy among
the 4 of you so that everyone gets at least 2 pieces of candy, but nobody gets a
dozen or more pieces of candy?
Your Answer:
Answer
Chapter 2 Solutions
The Heart of Mathematics: An Invitation to Effective Thinking
Ch. 2.1 - Muchos mangos. You inherit a large crate of...Ch. 2.1 - Packing balk. Your best friend is about to turn 21...Ch. 2.1 - Alternative rock. You have an empty CD rack...Ch. 2.1 - The Byrds. You have 16 new CDs to put on your...Ch. 2.1 - For the birds. Explain the Pigeonhole principle.Ch. 2.1 - Treasure chest (ExH). Someone offers to give you a...Ch. 2.1 - Order please. Order the following numbers from...Ch. 2.1 - Penny for your thoughts (H). Two thousand years...Ch. 2.1 - Twenty-nine is hat. Find the most interesting...Ch. 2.1 - Perfect numbers. The only natural numbers that...
Ch. 2.1 - Many fold (S). Suppose you were able to take a...Ch. 2.1 - Only one cake. Suppose we had a room filled with...Ch. 2.1 - For the birds. Years ago, before overnight...Ch. 2.1 - Sock hop (ExH). You have 10 pain of socks, five...Ch. 2.1 - The last one. Here is a game to be played with...Ch. 2.1 - See the three. What proportion of the first 1000...Ch. 2.1 - See the three II (H). What proportion of the first...Ch. 2.1 - See the three III. Explain why almost all...Ch. 2.1 - Commuting. One hundred people in your neighborhood...Ch. 2.1 - RIP (S). The Earth has more than 6.8 billion...Ch. 2.1 - Say the sequence. The following are the first few...Ch. 2.1 - Lemonade. You want to buy a new car, and you know...Ch. 2.1 - With a group of folks. In a small group, discuss...Ch. 2.1 - Ramanujan noodles (H). Ramanujan tells you that...Ch. 2.1 - Bird count. You want to know how many pigeons you...Ch. 2.1 - Many pennies. Suppose you have a 33 checkerboard...Ch. 2.1 - Wheres the birdie? One of your pigeons decides to...Ch. 2.2 - Fifteen Fibonaccis. List the first 15 Fibonacci...Ch. 2.2 - Born . What is the precise number that the symbol ...Ch. 2.2 - Tons of ones. Verify that 1+11+11 equals 3/2.Ch. 2.2 - Twos and threes. Simplify the quantities 2+22+22...Ch. 2.2 - The amity of . Solve the following equations for...Ch. 2.2 - Baby bunnies. This question gave the Fibonacci...Ch. 2.2 - Discovering Fibonacci relationships (S). By...Ch. 2.2 - Discovering more Fibonacci relationships, By...Ch. 2.2 - Late bloomers (ExH). Suppose we start with one...Ch. 2.2 - A new start. Suppose we build a sequence of...Ch. 2.2 - Discovering Lucas relationships. By experimenting...Ch. 2.2 - Still more Fibonacci relationships. By...Ch. 2.2 - Even more Fibonacci relationships. By...Ch. 2.2 - Discovering Fibonacci and Lucas relationships. By...Ch. 2.2 - The enlarging area paradox (S). The square shown...Ch. 2.2 - Sum of Fibonacci (H). Express each of the...Ch. 2.2 - Some more sums. Express each of the following...Ch. 2.2 - Fibonacci nim: The first move. Suppose you are...Ch. 2.2 - Fibonacci nim: The first move II. Suppose you are...Ch. 2.2 - Fibonacci nim: The first move III. Suppose you are...Ch. 2.2 - Fibonacci nim: The next move. Suppose you are...Ch. 2.2 - Fibonacci nim: The next move II. Suppose you are...Ch. 2.2 - Prob. 23MSCh. 2.2 - Beat your friend. Play Fibonacci nim with a...Ch. 2.2 - Beat another friend. Play Fibonacci nim with...Ch. 2.2 - Discovering still more Fibonacci relationships. By...Ch. 2.2 - Finding factors (S). By experimenting with...Ch. 2.2 - The rabbits rest. Suppose we have a pair of baby...Ch. 2.2 - Digging up Fibonacci roots. Using the square root...Ch. 2.2 - Tribonacci. Lets start with the numbers 0, 0, 1,...Ch. 2.2 - Prob. 31MSCh. 2.2 - Prob. 32MSCh. 2.2 - Prob. 33MSCh. 2.2 - A big fib (ExH). Suppose we have a natural number...Ch. 2.2 - Decomposing naturals (H). Use the result of...Ch. 2.2 - How big is it? Is it possible for a Fibonacci...Ch. 2.2 - Too small. Suppose we have a natural number that...Ch. 2.2 - Beyond Fibonacci. Suppose we create a new sequence...Ch. 2.2 - Generalized sums. Let Gn be the generalized...Ch. 2.2 - Its hip to be square (H). Adapt the methods of...Ch. 2.2 - Personal perspectives. Write a short essay...Ch. 2.2 - With a group of folks. In a small group, discuss...Ch. 2.2 - Here we celebrate the power of algebra as a...Ch. 2.2 - Finding x(H). Solve for x:x=1+6x.Ch. 2.2 - Appropriate address. Fibonaccis house number is...Ch. 2.2 - Zen bunnies. Your rabbits do yoga every morning in...Ch. 2.2 - The power of gold (H). In 1843 Jacques Binet (not...Ch. 2.3 - PrimaI Instincts. List the first 15 prime numbers.Ch. 2.3 - Fear factor. Express each of the following numbers...Ch. 2.3 - Odd couple. If n is an odd number greater than or...Ch. 2.3 - Tower of power. The first four powers of 3 are...Ch. 2.3 - Compose a list. Give an infinite list of natural...Ch. 2.3 - A silly start. What is the smallest number that...Ch. 2.3 - Waking for a nonprime. What is the smallest...Ch. 2.3 - Always, sometimes, never. Does a prime multiplied...Ch. 2.3 - The dividing line. Does a nonprime divided by a...Ch. 2.3 - Prime power. Is it possible for an extremely large...Ch. 2.3 - Nonprimes (ExH). Are there infinitely many natural...Ch. 2.3 - Prime test. Suppose you are given a number n and...Ch. 2.3 - Twin primes. Find the first 15 pairs of twin...Ch. 2.3 - Goldbach. Express the first 15 even numbers...Ch. 2.3 - Odd Goldbach (H). Can every odd number greater...Ch. 2.3 - Still the 1 (S). Consider the following sequence...Ch. 2.3 - Zeros and ones. Consider the following sequence of...Ch. 2.3 - Zeros, ones, and threes. Consider the following...Ch. 2.3 - A rough count. Using results discussed in this...Ch. 2.3 - Generating primes (H). Consider the list of...Ch. 2.3 - Generating primes II. Consider the list of...Ch. 2.3 - Floating in factors. What is the smallest natural...Ch. 2.3 - Lucky 13 factor. Suppose a certain number when...Ch. 2.3 - Remainder reminder (S). Suppose a certain number...Ch. 2.3 - Remainder roundup. Suppose a certain number when...Ch. 2.3 - Related remainders (H). Suppose we have two...Ch. 2.3 - Prime differences. Write out the first 15 primes...Ch. 2.3 - Minus two. Suppose we take a prime number greater...Ch. 2.3 - Prime neighbors. Does there exist a number n such...Ch. 2.3 - Perfect squares. A perfect square is a number that...Ch. 2.3 - Perfect squares versus primes. Using a calculator...Ch. 2.3 - Prime pairs. Suppose that p is a prime number...Ch. 2.3 - Remainder addition. Let A and B be two natural...Ch. 2.3 - Remainder multiplication. Let A and B be two...Ch. 2.3 - A prime-free gap (S). Find a run of six...Ch. 2.3 - Prime-free gaps. Using Mindscape 35, show that,...Ch. 2.3 - Three primes (ExH). Prove that it is impossible to...Ch. 2.3 - Prime plus three. Prove that if you take any prime...Ch. 2.3 - A small factor. Prove that if a number greater...Ch. 2.3 - Prime products (H). Suppose we make a number by...Ch. 2.3 - Seldom prime. Suppose that x is a natural number...Ch. 2.3 - A special pair of twins. A composite number x is...Ch. 2.3 - Special K p. A prime p satisfies the equation...Ch. 2.3 - Prob. 48MSCh. 2.3 - One real root (H). Find one value of x for which...Ch. 2.4 - A flashy timepiece. You own a very expensive watch...Ch. 2.4 - Living in the past. Your watch currently reads...Ch. 2.4 - Mod prods. Which number from 0 to 6 is equivalent...Ch. 2.4 - Prob. 4MSCh. 2.4 - A tower of mod power. Reduce 13 mod 11. Reduce 132...Ch. 2.4 - Hours and hours. The clock now reads 10:45. What...Ch. 2.4 - Days and days. Today is Saturday. What day of the...Ch. 2.4 - Months and months (H). It is now July. What month...Ch. 2.4 - Celestial seasonings (S). Which of the following...Ch. 2.4 - SpaghettiOs. Which of the following is the correct...Ch. 2.4 - Prob. 11MSCh. 2.4 - Tonic water. Which of the following is the correct...Ch. 2.4 - Real mayo (H). The following is the UPC for...Ch. 2.4 - Applesauce. The following is the UPC for Lucky...Ch. 2.4 - Grand Cru. The following is the UPC for Celis Ale...Ch. 2.4 - Mixed nuts. The following is the UPC for Planters...Ch. 2.4 - Blue chips. The following is the UPC for Garden of...Ch. 2.4 - Lemon. The following is the UPC for RealLemon...Ch. 2.4 - Decoding (S). A friend with lousy handwriting...Ch. 2.4 - Check your check. Find the bank code on your...Ch. 2.4 - Prob. 21MSCh. 2.4 - More bank checks (ExH). Determine the check digits...Ch. 2.4 - UPC your friends. Have a friend find a product...Ch. 2.4 - Whoops. A UPC for a product is Explain why the...Ch. 2.4 - Whoops again. A bank code is Explain why the...Ch. 2.4 - Mod remainders (S). Where would 129 be on a mod 13...Ch. 2.4 - More mod remainders. Where would 2015 be on a mod...Ch. 2.4 - Money orders. U.S. Postal Money Orders have a...Ch. 2.4 - Airline tickets. An airline ticket identification...Ch. 2.4 - UPS. United Parcel Service uses the same check...Ch. 2.4 - Check a code. U.S. Postal Money Order serial...Ch. 2.4 - ISBN-13. The 13-digit book identification number,...Ch. 2.4 - ISBN-13 check (H). Find the check digits for the...Ch. 2.4 - ISBN-13 error. The ISBN-13 978-4-1165-9105-4 is...Ch. 2.4 - Brush up your Shakespeare. Find a book containing...Ch. 2.4 - Mods and remainders. Use the Division Algorithm...Ch. 2.4 - Catching errors (H). Give some examples in which...Ch. 2.4 - Why three? In the UPC, why is 3 the number every...Ch. 2.4 - A mod surprise. For each number n from 1 to 4,...Ch. 2.4 - A prime magic trick. Pick a prime number and call...Ch. 2.4 - One congruence, two solutions. Find two different...Ch. 2.4 - Chinese remainder. Find one natural number x that...Ch. 2.4 - More remainders. Find one natural number z that...Ch. 2.4 - Quotient coincidence. Suppose x is a natural...Ch. 2.4 - Prob. 49MSCh. 2.5 - What did you say? The message below was encoded...Ch. 2.5 - Secret admirer. Use the scheme on page 99 to...Ch. 2.5 - Setting up secrets. Let p=7 and q=17. Are p and q...Ch. 2.5 - Second secret setup. Let p=5 and q=19. Are p and q...Ch. 2.5 - Secret squares. Reduce the following quantities:...Ch. 2.5 - Petit Fermat 5. Compute 24 (mod 5). Compute 44...Ch. 2.5 - Petit Fermat 7. Compute 46 (mod 7). Compute 56...Ch. 2.5 - Top secret (ExH). In our discussion, the two...Ch. 2.5 - Middle secret (H). In our discussion, the two...Ch. 2.5 - Prob. 10MSCh. 2.5 - Creating your code (S). Suppose you wish to devise...Ch. 2.5 - Using your code. Given the coding scheme you...Ch. 2.5 - Public secrecy. Using the List in Mindscape 12,...Ch. 2.5 - Going public. Using the list in Mindscape 12, with...Ch. 2.5 - Secret says (H). Using the list in Mindscape 12,...Ch. 2.5 - Big Fermat (S). Compute 5600 (mod 7). (Hint:...Ch. 2.5 - Big and powerful Fermat (ExH). Recall how...Ch. 2.5 - The value of information. How large should the...Ch. 2.5 - Something in common. Suppose that p is a prime...Ch. 2.5 - Faux pas Fermat. Compute 15 mod 6, 25 mod 6, 35...Ch. 2.5 - Breaking the code. If you could factor a large...Ch. 2.5 - Signing your name. Suppose you get a message that...Ch. 2.5 - Prob. 27MSCh. 2.5 - FOILed! FOIL the expression (a1)(q1). Suppose you...Ch. 2.5 - FOILed again! FOIL the expression (x1)(y1)....Ch. 2.5 - Secret primes. You know that p and q are primes...Ch. 2.5 - Prob. 31MSCh. 2.6 - A rational being. What is the definition of a...Ch. 2.6 - Fattened tractions. Reduce these overweight...Ch. 2.6 - Prob. 3MSCh. 2.6 - Decoding decimals. Show that each of the decimal...Ch. 2.6 - Odds and ends. Square the numbers from 1 to 12. Do...Ch. 2.6 - Irrational rationalization. We know that 2 ¡s...Ch. 2.6 - Rational rationalization. We know 2/5 and 7/3 are...Ch. 2.6 - Rational or not (ExH). For each of the following...Ch. 2.6 - Irrational or not. Determine if each of the...Ch. 2.6 - In Mindscapes 10-16, show that the value given is...Ch. 2.6 - In Mindscapes 10-16, show that the value given is...Ch. 2.6 - In Mindscapes 10-16, show that the value given is...Ch. 2.6 - In Mindscapes 10-16, show that the value given is...Ch. 2.6 - In Mindscapes 10-16, show that the value given is...Ch. 2.6 - In Mindscapes 10-16, show that the value given is...Ch. 2.6 - In Mindscapes 10-16, show that the value given is...Ch. 2.6 - An irrational exponent (H). Suppose that E is the...Ch. 2.6 - Another irrational exponent. Suppose that E is the...Ch. 2.6 - Still another exponent (ExH). Suppose that E is...Ch. 2.6 - Another rational exponent. Suppose that E is the...Ch. 2.6 - Rational exponent. Suppose that E is the number...Ch. 2.6 - Rational sums. Show that the sum of any two...Ch. 2.6 - Rational products. Show that the product of any...Ch. 2.6 - Root of a rational Show that (1/2) is irrational.Ch. 2.6 - Root of a rational (S). Show that (2/3) is...Ch. 2.6 - . Using the fact that is irrational, show that +3...Ch. 2.6 - 2. Using the fact that is irrational, show that 2...Ch. 2.6 - 2. Suppose that we know only that 2 is irrational....Ch. 2.6 - A rational in disguise. Show that the number (22)2...Ch. 2.6 - Prob. 30MSCh. 2.6 - More cube roots. Show that 33 is irrational.Ch. 2.6 - One-fourth root. Show that the fourth root of...Ch. 2.6 - Irrational sums (S). Does an irrational number...Ch. 2.6 - Irrational products (H). Does an irrational number...Ch. 2.6 - Irrational plus rational. Does an irrational...Ch. 2.6 - p. Show that for any prime number p,p ¡s an...Ch. 2.6 - pq. Show that, for any two different prime numbers...Ch. 2.6 - p+q. Show that, for any prime numbers p and q,p+q...Ch. 2.6 - 4. The square root of 4 is equal to 2, which is a...Ch. 2.6 - Sum or difference (H). Let a and b be any two...Ch. 2.6 - Rational x. Simplify the following expressions to...Ch. 2.6 - High 5. Suppose that x is a positive number...Ch. 2.6 - Dont be scared (H). Consider the scary equation....Ch. 2.6 - A hunt for irrationals. Find all solutions to the...Ch. 2.6 - A hunt for rationales. For any number x, the...Ch. 2.7 - X marks the X-act spot. On the number tine above,...Ch. 2.7 - Moving the point. Simplify each of the...Ch. 2.7 - Watch out for ones! Express 1/9 in decimal form....Ch. 2.7 - Real redundancy Suppose M=0.4999.... Then what...Ch. 2.7 - Being irrational. Explain what it means for a...Ch. 2.7 - Always, sometimes, never. A number with an...Ch. 2.7 - Square root of 5. The 5 has an unending decimal...Ch. 2.7 - A rational search (ExH). Find a rational number...Ch. 2.7 - Another rational search. Find a rational number...Ch. 2.7 - An Irrational search (H). Describe an irrational...Ch. 2.7 - Another irrational search. Describe an irrational...Ch. 2.7 - Your neighborhood. Suppose we tell you that we are...Ch. 2.7 - Another neighborhood. Suppose we tell you that we...Ch. 2.7 - In Mindscapes 14-16, express each fraction in its...Ch. 2.7 - In Mindscapes 14-16, express each fraction in its...Ch. 2.7 - In Mindscapes 14-16, express each fraction in its...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - In Mindscapes 17-25, express each number as a...Ch. 2.7 - Farey fractions. Let F be the collection of all...Ch. 2.7 - Even irrational. Show that the number...Ch. 2.7 - Odd irrational (H). Show that the number...Ch. 2.7 - A proof for . Suppose we look at the first one...Ch. 2.7 - Irrationals and zero. Is there an irrational...Ch. 2.7 - Irrational with 1s and 2s (S). Is it possible to...Ch. 2.7 - Irrational with 1s and some 2s. Is it possible to...Ch. 2.7 - Half steps. Suppose you are just a point and are...Ch. 2.7 - Half steps again (ExH). Suppose now that you are a...Ch. 2.7 - Cutting . Is it possible to cut up the interval...Ch. 2.7 - From infinite to finite. Find a real number that...Ch. 2.7 - Rationals (H). Show that, between any two...Ch. 2.7 - Irrationals. Show that, between any two different...Ch. 2.7 - Terminator. Show that if a rational number has a...Ch. 2.7 - Terminator II. Show that if the denominator of a...Ch. 2.7 - An unknown digit. Let x be a digit satisfying the...Ch. 2.7 - Prob. 46MSCh. 2.7 - Is y irrational? You decide to create the digits...Ch. 2.7 - Is z irrational? Follow the same construction as...Ch. 2.7 - Triple digits (H). Suppose a, b, and c are digits...
Additional Math Textbook Solutions
Find more solutions based on key concepts
A categorical variable has three categories, with the following frequencies of occurrence: a. Compute the perce...
Basic Business Statistics, Student Value Edition
A child has 12 blocks, of which 6 are black, 4 are red, 1 is white, and 1 is blue. If the child puts the blocks...
A First Course in Probability (10th Edition)
Read about basic ideas of statistics in Common Core Standards for grades 3-5, and discuss why students at these...
A Problem Solving Approach To Mathematics For Elementary School Teachers (13th Edition)
If the difference between a positive mixed number and a negative mixed number always, sometime, or never positi...
Pre-Algebra Student Edition
Interpreting a Decision In Exercises 43–48, determine whether the claim represents the null hypothesis or the a...
Elementary Statistics: Picturing the World (7th Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, subject and related others by exploring similar questions and additional content below.Similar questions
- In a bag, a child has 325 coins worth $19.50. There were three types of coins: pennies, nickels, and dimes. If the bag contained the same number of nickels as dimes, how many of each type of coin was in the bag?arrow_forwardAlice and Bill have four grandchildren, and they have three framed pictures of each grandchild. They wish to choose one picture of each grandchild to display on the piano in their living room, arranged from oldest to youngest. In how many ways can they do this?arrow_forwardUse the order of operations to show that (3+5)2is 64, and then use that numerical example to explain why (a+b)2a2+b2 .arrow_forward
- Determine if each is an expression or an equation: 23+6=29 (b) 737arrow_forwardTo get her daily intake of fruit for the day, Sasha eats a banana and 8 strawberries on Wednesday for a calorie count of 145. On the following Wednesday, she eats two bananas and 5 strawberries for a total of 235 calories for the fruit. How many calories are there in a banana? How many calories are in a strawberry?arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
Algebra for College StudentsAlgebraISBN:9781285195780Author:Jerome E. Kaufmann, Karen L. SchwittersPublisher:Cengage Learning
Intermediate AlgebraAlgebraISBN:9781285195728Author:Jerome E. Kaufmann, Karen L. SchwittersPublisher:Cengage Learning
Elementary AlgebraAlgebraISBN:9780998625713Author:Lynn Marecek, MaryAnne Anthony-SmithPublisher:OpenStax - Rice University
College AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage Learning
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Algebra for College Students
Algebra
ISBN:9781285195780
Author:Jerome E. Kaufmann, Karen L. Schwitters
Publisher:Cengage Learning
Intermediate Algebra
Algebra
ISBN:9781285195728
Author:Jerome E. Kaufmann, Karen L. Schwitters
Publisher:Cengage Learning
Elementary Algebra
Algebra
ISBN:9780998625713
Author:Lynn Marecek, MaryAnne Anthony-Smith
Publisher:OpenStax - Rice University
College Algebra
Algebra
ISBN:9781305115545
Author:James Stewart, Lothar Redlin, Saleem Watson
Publisher:Cengage Learning
Solve ANY Optimization Problem in 5 Steps w/ Examples. What are they and How do you solve them?; Author: Ace Tutors;https://www.youtube.com/watch?v=BfOSKc_sncg;License: Standard YouTube License, CC-BY
Types of solution in LPP|Basic|Multiple solution|Unbounded|Infeasible|GTU|Special case of LP problem; Author: Mechanical Engineering Management;https://www.youtube.com/watch?v=F-D2WICq8Sk;License: Standard YouTube License, CC-BY
Optimization Problems in Calculus; Author: Professor Dave Explains;https://www.youtube.com/watch?v=q1U6AmIa_uQ;License: Standard YouTube License, CC-BY
Introduction to Optimization; Author: Math with Dr. Claire;https://www.youtube.com/watch?v=YLzgYm2tN8E;License: Standard YouTube License, CC-BY