How many ways can five people, A, B, C, D, and E, sit in a row at a concert hall if A and B must sit together?
A) 48
B) 120
C) 12
D) 24

Question

Quizplus · Accepted Answer

Since A and B must sit together, we can treat them as a single unit. This means we have 4 units to arrange (AB, C, D, E). The number of ways to arrange these 4 units is 4! = 24. However, within the AB unit, A and B can switch places, adding another factor of 2. Therefore, the total number of arrangements is 24 * 2 = 48.

How Many Ways Can Five People, A, B, C, D