Free Practice Question
PS · Problem Solving
505-555
Combinations
Five friends, Frank, Grace, Henry, Isla, and Jack are arranged on a park bench. If Frank and Isla must not sit next to each other, how many unique seating arrangements can be made?
Answer Choices
Correct answer marked belowA
6
B
12
C
60
72
Correct
E
120
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Explanation
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Official Explanation
Official
The total number of arrangements for all 5 friends is calculated as 5! = 120. When Frank and Isla are treated as a single unit, the arrangements…
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Comments
2
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S
SuraiyaApr 14, 2025
Good question
K
KeerthikaApr 25, 2024
thanks!
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