MathDB

2

Part of 2010 Austria Beginners' Competition

Problems(1)

tree's problem with average Austria Beginners' Competition 2010 p2

Source:

10/3/2021
In a national park there is a group of sequoia trees, all of which have a positive integer age. Their average age is 4141 years. After a 20102010 year old building was destroyed by lightning, the average age drops to 4040 years. How many trees were originally in the group? At most, how many of them were exactly 20102010 years old?
(W. Janous, WRG Ursulinen, Innsbruck)
algebra