Probability and Data — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Five tally bundles plus 2 marks equal a count of 27.
Each bundle is five marks, and singles are added afterward to the total.
2. A bag holds 1 yellow, 1 green, and 2 blue marbles. Blue chance is 2 out of 4.
Probability counts matching items compared to the total items in the bag.
3. If 3 of 4 buttons are red, the probability of red is 3/4.
Total outcomes always sit below the line in a probability fraction.
4. Bars show 6 books and 10 toys. Toys beat books by 4.
Subtraction finds the gap between two bar heights on the same graph.
5. A spinner with 1 red and 3 white sections gives red a chance of 1/4.
Equal sections form the denominator in a spinner probability fraction.
6. If a coin lands heads about 1 in 2 flips, that is equally likely.
Equal outcomes mean each result is equally likely on a fair coin.
7. If a chart shows 9 apples and 11 pears, the total fruit count is 20.
Adding categories on a tally chart gives the combined total quickly.
8. Pulling a vowel from the letters A, E, I, O is certain.
When all items match the event, the outcome must always happen.
9. Drawing a red card from a black-only deck is impossible.
Zero matching outcomes mean an event can never happen at all.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
1 red marble in a bag of 2
→ 1/2 chance, equally likely
1/2 chance, equally likely
Rolling 8 on a standard die
→ Impossible event
Impossible event
Picking any letter from A to Z
→ Certain event
Certain event
1 winner out of 100 tickets
→ Unlikely event
Unlikely event
Probability words and fractions describe how often events should occur.