# Only 1 in 200 GCSE Maths students got this question right. Can you?

TLDRThis video script discusses a notoriously difficult GCSE Maths question that only 0.5% of students answered correctly. The presenter, without a calculator, tackles a quadratic equation, factorizes it successfully, and then explains why the expression cannot be a prime number given that 't' is a positive integer. The explanation hinges on the fact that neither factor of the broken-down expression can be one, a requirement for a number to be prime. The video is a testament to the presenter's mathematical prowess and a challenge to viewers to test their own skills.

### Takeaways

- π§ The video discusses a challenging GCSE Maths question that only 1 in 200 students got right.
- π The script begins with a mention of a previous video about difficult GCSE questions and introduces a new one from a calculator exam.
- π The presenter is in Lisbon without a calculator, but decides to analyze the questions to see if any can be done without one.
- π Statistics are presented, showing that only 10% of students got a particular question about drawing a frequency polygon right.
- π Another question about the total surface area of a hemisphere is mentioned, with the presenter suggesting it's not too difficult.
- π€ The script delves into trigonometry and Pythagoras, with the presenter noting that only 6.6% of students got these questions right.
- π The presenter considers a quadratic equation, stating that it should be straightforward with the right methods and tools.
- π’ The last question, which only 0.5% of students got right, involves factorizing a quadratic expression and explaining why it can't be prime.
- π The presenter explains the method to factorize the quadratic expression 2t squared plus 5t plus 2.
- π€ The explanation involves finding two numbers that add up to 5 and multiply to 4, then splitting and factorizing the expression.
- π The final part of the question asks why the expression can never be prime if 't' is a positive integer, which the presenter explains by considering the factors.
- π The presenter concludes that understanding the question's requirement to connect algebra with number theory is key to getting it right.

### Q & A

### What was the topic of the video discussed in the transcript?

-The video discussed the hardest GCSE Maths question, where a very low percentage of students got it right, and the speaker attempts to understand why.

### What is a frequency polygon mentioned in the transcript?

-A frequency polygon is a graph used in statistics to represent the distribution of a data set, which was part of the GCSE Maths question discussed.

### What is the significance of the number 0.2 in the transcript?

-The number 0.2 represents the percentage of students who got the last GCSE Maths question right, which was an extremely low percentage indicating the question's difficulty.

### What is the role of Pythagoras in the context of the video script?

-Pythagoras' theorem, which is used for calculating the lengths of the sides of a right triangle, is mentioned as part of the trigonometry section of the GCSE Maths question.

### What is the main mathematical concept discussed in the latter part of the transcript?

-The main mathematical concept discussed is factorizing quadratic equations and understanding why a particular quadratic expression cannot be a prime number.

### What is the expression that the speaker attempts to factorize in the video?

-The expression the speaker attempts to factorize is 2t^2 + 5t + 2.

### What is the method used by the speaker to factorize the quadratic expression?

-The speaker uses a method where they first find two numbers that add up to the coefficient of the linear term (5 in this case) and multiply to the product of the coefficient of the quadratic term (2) and the constant term (2), then they rewrite the expression to make it factorizable.

### Why can the expression 2t^2 + 5t + 2 never be a prime number if t is a positive integer?

-The expression can never be a prime number because, when factorized, it becomes (t + 2)(2t + 1). Since t is a positive integer, neither factor can equal one, which is a requirement for a number to be prime.

### What is the definition of a prime number as mentioned in the transcript?

-A prime number is a number that has only two factors: itself and one.

### What is the percentage of students who got the last question right according to the transcript?

-According to the transcript, only 0.5 percent of students got the last question right.

### What does the speaker conclude about the students who got the question right?

-The speaker concludes that if a student got the question right, they are in the top 0.5 percent of GCSE Maths students.

### Outlines

### π Analyzing Difficult GCSE Math Questions

The speaker revisits a series of challenging GCSE math questions, focusing on a calculator-based version. Despite being in Lisbon without a calculator, they decide to explore the questions, highlighting the importance of understanding frequency polygons and surface area calculations. They express curiosity about the difficulty level of the questions, noting that some involve basic trigonometry and Pythagorean theorem applications, which are fundamental. The speaker also mentions a quadratic equation, emphasizing its importance as a basic concept that should be easily solvable with the right methods or a calculator.

### π Factorizing Quadratics and Prime Number Theory

In this segment, the speaker demonstrates how to factorize a quadratic equation with a leading coefficient, using the specific example of 2t squared plus 5t plus 2. They explain the method of finding two numbers that sum and multiply to the required values, successfully breaking down the quadratic into (t + 2) and (2t + 1). Following this, the speaker addresses the second part of the question, which asks why this expression cannot be a prime number if t is a positive integer. They use prime number properties to argue that since t is positive, neither factor can equal one, which is a requirement for a number to be prime. This logical explanation leads to the conclusion that the expression cannot be prime, a concept that might be confusing for students but is crucial for understanding the relationship between algebra and number theory.

### Mindmap

### Keywords

### π‘GCSE

### π‘Frequency Polygon

### π‘Surface Area

### π‘Trigonometry

### π‘Pythagoras

### π‘Quadratic Equation

### π‘Factorize

### π‘Prime Number

### π‘Algebra

### π‘Number Theory

### Highlights

Introduction to a challenging GCSE Maths question.

Exploration of a calculator version of a difficult question.

The presenter is in Lisbon without a calculator.

Frequency polygon and basic statistics discussed.

10% of students got the total surface area question right.

Trigonometry and Pythagoras theorem mentioned.

Only 0.5% of students answered a quadratic equation correctly.

The presenter considers attempting a question without a calculator.

Explanation of factorizing a quadratic equation.

Method for factorizing when there's a coefficient in front of the squared term.

The presenter factors the equation 2t^2 + 5t + 2.

0.5% of students correctly answered the final question.

The final question involves prime number theory.

Explanation of why the expression cannot be a prime number.

Prime numbers can only have two factors: themselves and one.

The presenter concludes that the expression cannot be prime given t is a positive integer.

Congratulation to those who got the question right, placing them in the top 0.5% of GCSE students.