statistics · Year 3 · AC9M3P01
How likely? (probability in words)
We describe chance with words: impossible, unlikely, even chance, likely, certain. Compare how many outcomes you want to how many there are altogether. If a bag is all red, drawing red is certain; if there is no red, it is impossible. When reds and blues are equal it is an even chance. More reds than blues makes red likely; fewer makes it unlikely. Count the actual objects, not the number of colours — three reds and one blue is not 50/50, because there are far more reds.
Sample questions
A bag holds only 5 red counters. You take one counter without looking. How likely is it to be red? Answer with one of: impossible, unlikely, even chance, likely, certain.
- There are 5 counters in the bag and 5 of them are red.
- That is 5 out of 5, so drawing a red counter is certain.
Answer: certain
A bag holds only 4 red counters. You take one counter without looking. How likely is it to be red? Answer with one of: impossible, unlikely, even chance, likely, certain.
- There are 4 counters in the bag and 4 of them are red.
- That is 4 out of 4, so drawing a red counter is certain.
Answer: certain
A bag holds only 2 red counters. You take one counter without looking. How likely is it to be red? Answer with one of: impossible, unlikely, even chance, likely, certain.
- There are 2 counters in the bag and 2 of them are red.
- That is 2 out of 2, so drawing a red counter is certain.
Answer: certain