Success Homeschool

Primary 6 Mathematics · Probability as numbers

Name: ______________________

Date: ____________

1. What is the probability of an impossible event?
- ☐ (a) 0
- ☐ (b) 1
- ☐ (c) 0.5
- ☐ (d) 100
2. What is the probability of rolling a 5 on a standard six-sided die?
- ☐ (a) 1/5
- ☐ (b) 1/6
- ☐ (c) 5/6
- ☐ (d) 1/2
3. A bag holds 4 red and 6 blue counters. What is the probability of choosing red, written as a decimal?
- ☐ (a) 0.4
- ☐ (b) 0.6
- ☐ (c) 0.04
- ☐ (d) 4
4. Which of these probabilities shows the most likely event?
- ☐ (a) 0.2
- ☐ (b) 35%
- ☐ (c) 1/2
- ☐ (d) 0.45
5. A fair coin is flipped. What is the probability of heads, written as a percentage?
6. A spinner has 8 equal sections and 2 of them are green. What is the probability of landing on green, as a fraction in simplest form? (Type your answer like 1/2.)
7. A standard die is rolled 120 times. About how many times would you expect to roll a 3?
8. A coin is flipped 50 times and lands heads 28 times. What percentage of the flips were heads?

Answer sheet

1. 0 — Impossible events have a probability of 0, the lowest point on the probability scale.
2. 1/6 — There are 6 equally likely outcomes and only one of them is a 5, so the probability is 16.
3. 0.4 — There are 10 counters and 4 are red, so the probability is 410 = 0.4.
4. 1/2 — Write them all as decimals: 0.2, 0.35, 0.5 and 0.45. The largest is 0.5, which is 12.
5. 50% — Heads is one of two equally likely outcomes: 12 = 0.5 = 50%.
6. 1/4 — 2 of the 8 equal sections are green: 28 = 14.
7. 20 — The probability of a 3 is 16, and 16 × 120 = 120 ÷ 6 = 20.
8. 56% — 2850 = 56100 = 56%. This is a little more than the expected 50%, which is normal.