Sarah Dunn, Madras College, St Andrew's, Scotland and Soh Yong
Sheng, Raffles Institution, Singapore both solved this in the
same way. You write the word EUROMATHS by starting at the top
left hand corner and taking the next letter by stepping one step
down or one step to the right in this array.
We draw a grid denoting the number of moves possible to reach
each place. The number of possible routes are calculated by
adding the number of the gridplace on the left and top, and if it
is on the extreme left or top then there is only 1 route to get
there. The number added will be correct as the square can only be
accessed through these squares. There are altogether 70 possible
ways.
Can you generalise this result to a 6 by 6 square, or a 7 by 7
square ... or an n by n square? Have you seen this pattern
before? You may like to try a 6 by 6 array written in a slightly
different formation.
| M |
| A A |
| T T T |
| H H H H |
| E E E E E |
| M M M M M M |
| A A A A A |
| T T T T |
| I I I |
| C C |
| S |