Sudoku Challenge

Have you heard of 'Sudoku'? According to Wikipedia, Sudoku, originally called "Number Place", is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 sub-grids that compose the grid (also called "boxes", "blocks", "regions", or "sub-squares") contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which typically has a unique solution.


Here is a sample of a Sudoku puzzle:

Can you solve it? Not to worry if you can't! Only the participants of the 7th Inter-School Sudoku Challenge, of which Henderson Secondary School is participating, have to worry. The competition takes place on the 26th of March 2013 and it is a time where Sudoku lovers gather and compete under time constraints and stress for the honour of being the best Sudoku solver.