JOHN HAS A BOARD WITH 11 SQUARES. HE PUTS A COIN IN EACH OF EIGHT...

13. John has a board with 11 squares. He puts a coin in each of eight neighbouring squares

without leaving any empty squares between the coins. What is the maximum number

of squares in which one can be sure that there is a coin?

(A) 1 (B) 3 (C) 4 (D) 5 (E) 6