January 1998
 Puzzle No. 4  Three doors

Here is this issue's puzzle.
 Solution to Puzzle No. 3  birth dates

The following people submitted correct answers:
 Leigh Dyment, Summerside, PE, Canada.
 Arthur Stratford, Cambridge, England.
 Surya, Memphis, TN, USA.
 Andrew Williams, Sussex, England.  The taxi problem revisited

Following on from this issue's article "Image analysis  a modern application of mathematics", we revisit the taxi problem from issue no. 2 (see "The taxi problem").
 The coin tossing problem

Following on from this issue's article "What a coincidence!", this page on coin tossing takes you through the calculation of the length of longest run of heads in n coin tosses.