What is the minimum number of pennies that can be placed upon a table so that each penny touches three, and only three, others?

(All the pennies must lie flat on the table.)

(In reply to re: is 4 not ok ?? by Charlie)

i'm a n00b, so i dunno if the solution's here or not, but afaik you arrange three touching pennies in a triangle and then put the fourth on top so that it covers all three right?

Posted by dr pyser on 2003-12-29 05:18:18