In-a-great-reunion-each-person-knows-at-least-two-different-persons-in-there-Show-that-this-statement-implies-that-exists-one-person-who-has-to-know-everyone-

Question Number 6464 by nburiburu last updated on 27/Jun/16

“ I n a g r e a t r e u n i o n e a c h p e r s o n k n o w s

a t l e a s t t w o d i f f e r e n t p e r s o n s i n {t h e r e}^{″} . S h o w

t h a t t h i s s t a t e m e n t i m p l i e s t h a t e x i s t s

o n e p e r s o n w h o h a s t o k n o w e v e r y o n e .

Commented by prakash jain last updated on 27/Jun/16

1 knows 2 3

2 knows 3 4

and so on

n knows 1 2

everyone knows 2 persons and noone knows

everyone .

Did i misunderstand the question ?

Commented by nburiburu last updated on 28/Jun/16

B e c a r e f u l :

i f 2 k n o w s 3 4 a n d 1 k n o w s 2 3 t h e n

2 a l s o k n o w s 1 .

S o t h e r e l a t i o n s h i p i s i n t w o w a y s .

A l s o, i f y o u s e l e c t a n y s u b g r o u p o f

t w o p e r s o n s y o u s h o u l d h a v e t o s e e i n

e a c h p e r s o n 2 r e l a t i o n s e x t e r n a l t o

t h e s u b g r o u p m a d e .

Commented by prakash jain last updated on 28/Jun/16

Thanks . I understand the question now .