Comments for

Comment on Crossing the bridge. by cookla

cookla — Tue, 15 Dec 2009 14:52:04 +0000

1 and 2 across (2 minutes)
1 goes back (3 minutes)
5 and 10 go across (13 minutes)
2 goes back (15 minutes)
1 and 2 cross (17 minutes) – and everyone safe and sound

Comment on mid-semester by cookla

cookla — Sat, 25 Oct 2008 04:04:50 +0000

Note that a bracelet can be rotated or flipped over without changing the basic pattern.
Here is one way to count the possibilities: place all four red beads. There are now four gaps in which
we can place the yellow beads. 1) Place one in each gap. 2) Place all four in one gap. 3 & 4) Place
one in one gap and three in another – either adjacent or opposite. 5 & 6) Place two in each of two
gaps – either opposite or adjacent. 7 & 8) Place two in one gap and one in each of two other
gaps. The two and the empty gap can be either opposite or adjacent.

Comment on Just another weekend. by cookla

cookla — Tue, 16 Sep 2008 02:24:12 +0000

Solution: 102564