Question

Find the number of ways in which 4 people E, F, G, H, A, C can be seated at a round table, such that E and F must always sit together.

(a) 32

(b) 290

(c) 124

(d) 48

I have been asked this question by my school principal while I was bunking the class.

Origin of the question is Counting in section Counting of Discrete Mathematics

Answer 1

Correct option is (d) 48

The best I can explain: E and F can sit together in all arrangements in 2! Ways. Now, the arrangement of the 5 people in a circle can be done in  (5 – 1)! or 24 ways. Therefore, the total number of ways will be 24 x 2 = 48.