Out of 10 contestants, six are to be selected for the final round of a competition - HSC - SSCE Mathematics Extension 1 - Question 10 - 2020 - Paper 1
Question 10
Out of 10 contestants, six are to be selected for the final round of a competition. Four of those six will be placed 1st, 2nd, 3rd and 4th.
In how many ways can thi... show full transcript
Worked Solution & Example Answer:Out of 10 contestants, six are to be selected for the final round of a competition - HSC - SSCE Mathematics Extension 1 - Question 10 - 2020 - Paper 1
Step 1
Step 1: Selecting the Contestants
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Answer
First, we need to choose 6 contestants from a total of 10. The number of ways to choose 6 from 10 can be calculated using the combination formula, which is given by:
C(n,r)=r!(n−r)!n!
Here, we have:
C(10,6)=6!4!10!
Step 2
Step 2: Arranging the Selected Contestants
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Answer
After selecting the contestants, we need to arrange 4 of them in the 1st, 2nd, 3rd, and 4th positions. The number of ways to arrange 4 contestants is given by the factorial of 4, which is:
4!
Step 3
Step 3: Total Number of Ways
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The total number of ways to select and arrange the contestants is the product of the results from Step 1 and Step 2:
Total Ways=C(10,6)×4!=6!4!10!×4!=6!10!
Step 4
Final Conclusion
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Thus, the total number of ways this process can be carried out is: