Worksheets · Foundation and Higher

Exhaustive outcomes and experimental probability

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

1. Question 1Non-calculator · 2 marks

   (a) A machine selects one of three symbols: a star, a circle or a square. The probability of a star is 0.28 and the probability of a circle is 0.47. What is the probability of a square? (2)

   1. 0.19
   2. 0.25
   3. 0.75
   4. 1.25
2. Question 2Non-calculator · 4 marks

   The only possible outcomes of a game are win, draw and lose. The probabilities of win and draw are $3/20$ and $1/5$.

   (a) Find the probability of losing. (2)

   (b) The game is played 200 times. Find the expected number of losses. (2)
3. Question 3Non-calculator · 4 marks

   A spinner can land on $A$, $B$, $C$ or $D$. P($A$) $= 2x$, P($B$) $= x + 0.1$, P($C$) $= 0.3$ and P($D$) $= x$.

   (a) Work out P($B$). (3)

   (b) The spinner is spun 200 times. Work out an estimate for the number of times it lands on $B$. (1)