The five girls, named G1, G2,…G5 arranged the round-table sitting so that between each two of them there were at least two out of 12 boys , B1, B2,…B12.

In how many ways is such arrangement possible?

(In reply to re(3): solution by Charlie)

Ah!   I think I must have keyed in 5 instead of 15 and then I made a mental multiplication error.  I have corrected my original post.

Edited on October 4, 2023, 8:13 am

Posted by Larry on 2023-10-03 21:59:51