Basic Probability Worksheet

This worksheet covers Basic Probability: picking letters from a word, conditions on a set, cards, combining events with OR and NOT, and experimental vs theoretical probability.

There are $20$ questions in total. Show your working where a calculation is involved. Work on paper, then check against the lessons if you get stuck.

Q1. In the word GIGGLE, what letter is most likely to be picked at random, and what is its probability?

Q2. In the word BUBBLE, what letter is most likely to be picked at random, and what is its probability?

Q3. In the word PUPPET, what letter is most likely to be picked at random, and what is its probability?

Q4. From the set $8,13,21,34,45,16,27$ — find the probability of picking a number that is even.

Q5. From the set $5,9,12,17,24,31,18,7$ — find the probability of picking a number that is a multiple of $3$.

Q6. One card is drawn at random from a standard deck. Find $P(\text{Ace})$.

Q7. One card is drawn at random. Find $P(\text{spade})$.

Q8. One card is drawn at random. Find $P(\text{face card})$ — Jack, Queen, or King.

Q9. One card is drawn at random. Find $P(\text{a card numbered }2,4,6,8,\text{or }10,\text{any suit})$.

Q10. A bag has $50$ counters: $20$ red, $12$ blue, $10$ green, $8$ yellow. Find $P(\text{red or green})$.

Q11. Using the same bag, find $P(\text{not blue})$.

Q12. Using the same bag, find $P(\text{blue or yellow})$.

Q13. A jar has $24$ balls: $9$ white, $7$ black, $5$ orange, $3$ purple. Find $P(\text{white or orange})$.

Q14. Using the same jar, find $P(\text{not purple})$.

Q15. A coin was flipped $100$ times: $58$ heads, $42$ tails. Find the experimental probability of heads.

Q16. Using the same trial, what is the theoretical probability of heads, and is the coin close to fair?

Q17. A spinner with $4$ equal sections (W, X, Y, Z) was spun $80$ times: W = 22$$,X$= 18$,Y$= 21$,Z$= 19$. Find the experimental probability of landing on Y.

Q18. Using the same spinner, what is the theoretical probability of landing on Y?

Q19. A die was rolled $90$ times, landing on $2$ seventeen times. Find the experimental probability of rolling a $2$.

Q20. Using the same die, what is the theoretical probability of rolling a $2$, and is the die close to fair?