Open problems solution.

1. Open problem: How many trees?
• Estimate the number of trees in the country of your
choice.
• Explain how the choice was made + your method.
Task from France
Presentation by Ariana Kornejeva(LV)

2. Our group
• Tutor: Esa Oila (FIN)
• Students: Maximilian Kamphaus(GER),
Niklas Willen(GER), Polina Lobanova(LV)
and Ariana Kornejeva(LV)

3. Our messaging

4. Our choice is to find out the number of
trees in Latvia

5. 1hypothesis
For each person living on Earth, there are 422
trees.
• https://geektimes.ru/post/261364/
Latvia has 1,957,200 inhabitants.
1957200 * 422= 825938400 (trees)

6. 2 hypothesis
64589 km2 - territory of Latvia
40% - forests in Latvia
(information from Wikipedia)
25 trees – in the area of 100 m2
(We counted in the forest)

7. Calculations
1)
X (km2) - territory of forests in Latvia
100% - 64589 km2
40% - x km2
x = (40*64589) / 100 = 25836 km2
25836 (km2) – territory of forests in Latvia

8. Calculations
2)
100 m2 = 0,001 km2
X(trees) – trees in the forests
25 trees - 0,001 km2
X trees - 25836 km2
x= (25* 25836)/ 0,001= 645900000 trees
645900000 (trees) – in the forests in Latvia

9. Conclusions
• 1 hypothesis- 825938400 (trees)
• 2 hypothesis- 645900000 (trees)
There is a difference between the 1
and 2 hypotheses, because in the 2
hypothesis we have counted trees
just in the forests of Latvia. It is
impossible to count trees near
roads and in private gardens.

10. Our solution
•In Latvia, approximately
820 million trees grow