Stage: 3 Challenge Level: 
| Christmas trees are planted in a rectangular array of 10 rows and 12 columns. The farmer chooses the shortest tree in each of the columns and then marks the tallest of these 12 shortest trees with a letter A. Then the farmer chooses the tallest tree from each of the rows and marks the shortest of these 10 tallest trees with a letter B. Which is the taller tree, A or B? |  |
Time. Visualising. Mathematical modelling. Real world. Selecting and using information. Mathematical reasoning & proof. Tabular data. Maximise/minimise/optimise. Speed. Inequality/inequalities.
Published December 1998.
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