Problem P. 3857. (January 2006)
P. 3857. Thomas is long-sighted. He is able to see clearly only those objects which are at least 1 m away. Find the power of the glasses through which he is able to read a book 25 cm away from his eyes.
Deadline expired on 13 February 2006.
|116 students sent a solution.|
|3 points:||85 students.|
|0 point:||23 students.|
|Unfair, not evaluated:||8 solutions.|