Worked examples
Two examples
Example 1
From 6 workers, a committee of 2 is chosen. How many committees?
- Ordered choices: 6 × 5 = 30.
- Each pair is counted twice (A then B, B then A): 30 ÷ 2.
Answer: 15
Example 2
From 7 people, a team of 3 is chosen. How many teams?
- 7 × 6 × 5 = 210 ordered choices.
- Each team can be listed in 3 × 2 × 1 = 6 orders: 210 ÷ 6.
Answer: 35
Where this is taught: Quiz 34: Probability and Counting, “When the order matters, and when it does not”
The drill
Ten problems
This drill also has challenge problems. They use the same skill, set up the way the GED test sometimes sets up a problem, so that it looks new at first.
How many:
Type each answer, then press Check my answers at the bottom. Commas in large numbers are fine.Write each answer on the line. The answer key, with the reasoning, is on the last page.