The 4-member family can be seated in 4! ways.
The two brothers can be seated together in 2! ways.
Therefore, the total number of ways is
[tex] \frac{4!}{2!} = \frac{4.3.2.1}{2.1} =4*3=12[/tex]
Diagrammatically, the result is shown in the figure below. The two brothers are family members 3 and 4, shown in shaded color.
Answer: 12 ways.
