The probability scale

Worksheet: The probability scale

Name:Class:

Answer the questions.

1. Which number describes an event that is impossible?
   a) 0b) 0.5c) 1d) 10
2. Which probability describes an event that is certain to happen?
   a) 0b) 0.5c) 1d) 100
3. A probability can never be greater than 1.
   a) Trueb) False
4. Which event has an even chance of happening?
   a) Getting heads when you flip a fair coinb) Rolling a 5 or 6 on a fair diec) Rolling a 6 on a fair died) Rolling a number less than 7 on a die
5. A fair die is rolled. What is the probability of getting a 4?
   a) 1/3b) 1/4c) 1/6d) 4/6
6. A bag has 3 red and 5 blue counters. One is picked at random. P(red) = ?
   a) 1/3b) 3/5c) 3/8d) 5/8
7. A fair die is rolled. What is the probability of an even number?
   a) 1/2b) 1/3c) 1/6d) 2/3
8. If P(rain) = 0.3, then the probability of no rain is 0.7.
   a) Trueb) False
9. The probability that a bus is late is 2/5. What is the probability it is not late?
   a) 1/5b) 2/5c) 3/5d) 5/3
10. The chance of winning a game is 0.65. What is the chance of not winning?
11. A spinner has 5 equal sections numbered 1 to 5. P(number greater than 3) = ?
    a) 1/5b) 2/3c) 2/5d) 3/5
12. If you flip a fair coin 10 times, you must get exactly 5 heads.
    a) Trueb) False
13. A coin lands heads 20 times in 50 flips. What is the experimental P(heads)?
    a) 1/2b) 2/5c) 20/30d) 3/5
14. A bag has 4 green and 6 yellow sweets. What is P(not green) as a fraction?
15. A drawing pin is dropped 40 times and lands point up 10 times. Experimental P(point up)?
16. A bag has 12 counters. P(blue) = 1/3. How many counters are blue?
    a) 3b) 4c) 6d) 9