Critical Line volume 30

Our Critical Line puzzles are the perfect activity for a winter’s night in. Enjoy this month’s puzzle by Jevon Fulbrook, which can be solved on your own or with a friend! 

For this month’s puzzle, work with the grid below. The red dotted outlined regions represent areas, within which you will need to enter shaded cells. Conditions are as follows:

  • You may place shaded cells neither horizontally nor vertically adjacent to one another.
  • Further, no horizontal or vertical sequence of blanks may intersect more than two regions
  • Numbered regions must contain exactly that many shaded cells.
  • All the white squares must be connected, horizontally and/or vertically


See the example and example solution below:

The puzzle below, does have multiple solutions, however the number of grey shaded cells in each column is unique. The answer I am requesting is the number of shaded cells in each column.

Good luck!

For your chance to win a $50 book voucher, send your solutions to


Volume 29 solution 

The expected number of rolls is (1+1/n)^n, which of course approaches e, as n tends to infinity.

Four correct responses were received, one from each of Tim Yip, Hemant Rupani, Thomas Zhou and Lawrence Uy.  The winner of the book voucher is Thomas Zhou! 

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