Question 17
EasyOriginal questionSeven runners reach the final of a school 400 m race. In how many ways can the gold, silver and bronze medals be awarded, if no two runners tie?
Show the answer and explanation
CorrectNot quiteAnswer B
Correct answer: B
Explanation
Gold can go to any of 7 runners, silver to any of the other 6, bronze to any of the remaining 5.
Ways .
Worth noting
35 is , which ignores which medal each runner gets. 343 is , which lets one runner win two medals.
- Concept
- Permutations: ordered selection
- Typical timeTypical
- 40 s
- Your timeYours
- —
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Ten questions from Counting and Basic Probability, at your own pace.