Answer: [tex]0.2\text{ million tons}[/tex]
Step-by-step explanation:
Given: In 1950, the use of coal in the us was 114.6 million tons.
The use of coal has decreased by 6.6% per year since then.
The use decreased in x years is given by the formula:-
[tex]y=A(1-r)^x[/tex],
Where A is the initial amount = 14.6 million tons.
r is the rate of decrease in decimal= 0.066
Then, the use of coal in 2010 (after 60 years)=[tex]y=14.6(1-0.066)^60[/tex]
[tex]=14.6(0.934)^{60}\\=14.6\times0.016626949\\=0.2427534\approx0.2\text{ million tons}[/tex]
Answer:
The amount of coal used in US in 2010 is [tex]1.9million\thinspace tons[/tex]
Step-by-step explanation:
Given in 1950, the use of coal in the us was 114.6 million tons. the use of coal has decreased by 6.6% per year. we have to estimate the amount of coal used in US in 2010.
Let us take the reference 1950 to 0
Amount of coal used in 1950 i.e 0 year is given by the equation
[tex]A=114.6(1-6.6\%)^t[/tex]
Now, to calculate the use of coal in 2010 i.e difference of years 2010-1950=60 i.e we have to estimate the amount of coal after 60 yrs is
[tex]A=114.6(1-6.6\%)^{60}[/tex]
⇒ [tex]A=114.6(0.934)^{60}[/tex]
⇒ [tex]A=1.90544839548\sim1.9million\thinspace tons[/tex]
The amount of coal used in US in 2010 is [tex]1.9million\thinspace tons[/tex]
