# math

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Using the formula v=20(1.222)^t and v is the value and t=0 which is the year 1971. What year will the set be worth 1500?

I input this into the formula to get
1500=20(1.222)
The 20(1.222) is 24.44 not sure how to figure out the year. I believe I just add the 24 years to 1971 to get 1995 but not sure about that.

• math -

V = 20(1.222)t = 1500,
20(1.222)t = 1500,
(1.222)^t = 1500 / 20 = 75,
Take the log of both sides:
t*log(1.222) = log75,
divide both sides by log(1.222):

t=log75/log(1.222)=1.8751 / 0.087071 =
21.53.

yr. = 1971 + 21 = 1992.

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