GCSE Secondary Maths Age 13-17 - Probability & Statistics: Probability - Explained

The video tutorial explains a probability problem involving black and white socks. It covers calculating the probability of drawing one black and one white sock, solving a quadratic equation, and determining the probability of drawing two black socks. The tutorial also discusses mark allocation and provides insights into solving similar problems in exams.

What is the total number of socks in the drawer?

• Y + 5

• 5

• Y

• 10

How do you calculate the probability of selecting a black sock first?

• Y / 5

• 5 / (Y + 5)

• 5 / Y

• Y / (Y + 5)

What is the probability of selecting a white sock after a black sock?

• 5 / (Y + 4)

• Y / (Y + 5)

• Y / (Y + 4)

• 5 / (Y + 5)

What is the combined probability of selecting one black and one white sock in any order?

• Y / (Y + 5)

• 6 / 11

• 5Y / (Y + 5)(Y + 4)

• 10Y / (Y + 5)(Y + 4)

What is the equation derived from the probability problem?

• 2y^2 - 20y + 50 = 0

• y^2 - 4y + 4 = 0

• y^2 + 5y + 6 = 0

• 3y^2 - 28y + 60 = 0

What method is used to solve the equation 3y^2 - 28y + 60 = 0?

• Completing the square

• Graphical method

• Factorization

• Substitution

What is the probability of selecting two black socks?

• 2 / 11

• 5 / 11

• 3 / 11

• 6 / 11

What is the value of Y when solving the quadratic equation?

• 4

• 6

• 10/3

• 5

Why is it important to practice with past papers?

• They provide similar questions in different contexts.

• They are easier than current papers.

• They have the same questions every year.

• They are not useful for new exams.

What should you do if you get an incorrect answer?

• Check your initial starting point.

• Ask a friend for help.

• Ignore it and move on.

• Guess the answer.