6. (20 points) The average life expectancy in the country of Gondor is 64 years. And the average life expectancy in the country of Númenor is 92 years. The average life expectancy in these two countries is 85 years. How many times does the population of Gondor differ from the population of Númenor

#
# Solution:

Let the population of Númenor be n, and the population of Gondor be $g$, then:

$64 \mathrm{~g}+92 \mathrm{n}=85(\mathrm{~g}+\mathrm{n})$

$64 g+92 n=85 g+85 n$

$7 \mathrm{n}=21 \mathrm{~g}$

$\mathrm{n}=3 \mathrm{~g}$

Answer: The population of Gondor is 3 times smaller

## Criteria:

| Points | Conditions for awarding |
| :---: | :--- |
| 20 points | Any complete and justified solution. |
| 10 points | The solution is generally correct, but an arithmetic error has been made |
| 0 points | The solution does not meet any of the criteria or only the answer is given |