Respuesta :
Answer:
Douglas fir trees are 350 in number and Ponderosa pine trees are 500 in number.
Step-by-step explanation:
Let the number of Douglas fir be denoted by 'x'
Let the number of Ponderosa pine trees be denoted by 'y'
The company paid average of $300 for each Douglas fir and $225 for each Ponderosa pine.
This gives, [tex]300x[/tex] for total Douglas fir trees and [tex]225y[/tex] for total Ponderosa pine trees.
Total amount paid by the company = 217500
Also given, there are 850 Douglas fir and Ponderosa pine trees which means ;
[tex]x+y=850[/tex] or
[tex]x=850-y[/tex] ......................(1)
[tex]300x+225y=217500[/tex] .............(2)
Putting the value of 'x' from equation 1 into equation 2.
[tex]300(850-y)+225y=217500[/tex]
Now, solving this equation we get,
[tex]255000-300y+225y=217500[/tex]
[tex]-300y+225y=217500-255000[/tex]
[tex]75y=37500[/tex]
[tex]y=500[/tex]
And we know [tex]x+y=850[/tex]
So, x = [tex]850-500=350[/tex]
Hence, Douglas fir trees are 350 in number and Ponderosa pine trees are 500 in number.