Question

5 people dine together at a round table. They dine together till each of them dines with different neighbours. Determine the number of days they dine together.

• A. 12
• B. 24
• C. 30
• D. 7
• E. 120

Answer 1

The correct option is A 12

Soln:

5 people can sit together around a round table in $(5-1)!=4!$ Ways. But in anticlockwise and clockwise arrangements each of them will have the same neighbour. So, no. of arrangements possible = $\frac{1}{2}(4!)=12$.

So, they dine together for 12 days.

Hence option (a)