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You deposit $600 in an account that pays 6% annual interest, compounded monthly. How long will it take for the balance to

triple?


With Steps!

User Blakharaz
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1 Answer

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Answer: To find out how long it will take for the balance to triple, we can use the formula for compound interest:

A = P * (1 + r/n)^(nt)

Where:

A is the final amount,

P is the initial deposit (600),

r is the annual interest rate (6%),

n is the number of times the interest is compounded per year (12 times per year, or monthly),

t is the time in years.

To find t, we'll set A equal to 3 * P and solve for t:

3 * P = P * (1 + r/n)^(nt)

Expanding the right-hand side:

3 * P = P * (1 + 0.06/12)^(12t)

Dividing both sides by P:

3 = (1 + 0.06/12)^(12t)

Taking the natural logarithm of both sides:

ln 3 = ln((1 + 0.06/12)^(12t))

Using the logarithmic rule for exponentiation:

ln 3 = (12t) * ln(1 + 0.06/12)

Dividing both sides by ln(1 + 0.06/12):

ln 3 / ln(1 + 0.06/12) = 12t

Using a logarithm calculator, we find that ln 3 / ln(1 + 0.06/12) = 15.57.

Finally, dividing by 12 to find t in years:

t = 15.57 / 12 = 1.298 years, or approximately 1 year and 4 months.

So, it will take approximately 1 year and 4 months for the balance to triple.

User Brendan Quinn
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