Worksheets · Foundation

Foundation statistics and probability clinic

3 exam-style questions. Answers and the mark for each step are on the last page.

1. Question 1Non-calculator · 3 marks

   $\xi = \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10\}$, $A = \{1, 2, 3, 4, 5\}$ and $B = \{2, 4, 6, 8, 10\}$.

   (a) List the members of $A \cap B$. (1)

   (b) A number is chosen at random from $\xi$. Work out $P((A \cup B)')$. (2)
2. Question 2Non-calculator · 4 marks

   Journey times are grouped as 0 to 10, 10 to 20 and 20 to 40 minutes, with frequencies 12, 15 and 11. A frequency polygon is to use class midpoints.

   (a) Write the coordinates of the middle plotted point. (2)

   (b) Find the total number of journeys. (2)
3. Question 3Non-calculator · 5 marks

   Spinner $X$ lands on red with probability 0.4. Spinner $Y$ lands on red with probability 0.25. Each spinner is spun once. The spinners are independent. A player wins if both land on red.

   (a) Work out the probability that the player wins. (2)

   (b) 200 people play. Each pays £1 and each winner receives £8. Work out how much money the game is expected to make. (3)