Free Practice Question
PS · Problem Solving
505-555
Combinations
In a group of 8 students, how many different ways can we select a president and a secretary, given that one individual cannot occupy both roles?
Answer Choices
Correct answer marked below56
Correct
B
8
C
64
D
7
E
15
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Explanation
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Official Explanation
Official
To solve this problem, we can use the filling space method. The position of president can be filled by any of the 8 students. Once the president is chosen, the position of secretary can…
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Comments
2
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M
MadhavJan 5, 2024
thankss
A
AshitaMar 6, 2024
Thank for sharing!!!
What this question tests
What it tests
Whether you can count arrangements and selections correctly — permutations vs. combinations.
Common trap
Overcounting: treating a selection as ordered when order does not matter, or forgetting to divide by duplicates.
Details
Difficulty
505-555
Type
PS
Category