Probability - BBC Math

Test Bite

You scored 10 out of 10

1. There are 20 counters in a box. Nine are yellow, 4 are black and 7 are green. What's the probability that a counter which is taken from the box without looking will be green? 

You said: ⁷/₂₀

2. What's the probability that a counter taken from the box without looking will be yellow or black? 

You said: ¹³/₂₀

3. What's the probability that a counter taken from the box without looking will be blue? 

You said: 0

4. What's the probability that a counter taken from the box without looking will not be black or green? 

You said: ⁹/₂₀

5. Two 6-sided dice are each marked 1, 1, 2, 2, 3, 3. Jot down all the possible pairs of numbers that you can get when the two dice are thrown. The pairs of numbers are added together to get a score. As the dice are only marked from 1-3, there's maximum score of

What's the probability of getting a score of 3? 

You said: ²/₉

6. What's the most likely score? 

You said: 4

7. What's the probability of getting a score of 6? 

You said: ¹/₉

8. Melanie has been recording how many times a drawing pin landed point-up after being thrown in the air. She threw the pin 50 times and found it landed point-up 9 times. What's the probability of it landing point-up in the next throw? 

You said: ⁹/₅₀

9. What's the probability it doesn't land point-up after the next throw? 

You said: ⁴¹/₅₀

10. The next day she throws the drawing pin in the air 200 times. Using her figures from the previous day, roughly how many times could she expect the drawing pin to land point-up? 

You said: 36