Information Display

The information display on a train shows letters by illuminating dots in a rectangular array. What fraction of the dots in this array is illuminated?

Problem



 

Image
Information Display



The information display on a train shows letters by illuminating dots in a rectangular 5 × 8 array.



In the letter 't' shown, what fraction of the dots in the array is illuminated?

 



 

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.