SOLUTION: The cost of electricity in a certain city is given by the formula A = p + prt for t and find how long it will take to double his money at the rates of 3%, 7%, and 10%

Question 778530: The cost of electricity in a certain city is given by the formula A = p + prt for t and find how long it will take to double his money at the rates of 3%, 7%, and 10%
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The cost of electricity in a certain city is given by the formula A = p + prt for t and find how long it will take to double his money at the rates of 3%, 7%, and 10%
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A + P(1+rt)
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At 3%:: Solve 1+0.03t = 2
0.03t = 1
t = 100/3
t = 33 1/3 years
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At 7%:: Solve 1 + 0.07t = 2
0.07t = 1
t = 100/7 = 14.29 years
----------------------
At 10%:: Solve 1 + 0.10t = 2
10%t = 1
t = 10 years
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Cheers,
Stan H.
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