In how many ways can 11 people stand in a row if two particular people must stand next to each other?

Answer and explanation

Correct answer: C.

  1. Step 1: Treat the pair as one block: units can be arranged in ways.
  2. Step 2: The pair can be ordered in 2 ways: .
Answer
.
Why not the others: : The restriction was ignored. : The two neighbours can also swap places. : The pair was not treated as a single block.

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In how many ways can 11… | Egyptian Scholastic Test (EST)