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How long does it take \(\$ 450\) to double at a simple interest rate of 14\(\% ?\)

Short Answer

Expert verified
It takes approximately 7.14 years for an amount of $450 to double at a simple interest rate of 14%.

Step by step solution

01

Establish Knowns and UnKnowns.

We know that the Principal (P) is $450, the rate (R) is 14%, and the Interest (I) earned should also be $450 (since the money needs to double). The time (T) is what we are trying to solve for.
02

Set Up the Interest Formula

The formula for simple interest is \(I = PRT / 100\). Substitute the known values: $450 = $450 * 14 * T / 100.
03

Solve the Equation for T

Solving the equation $450 = $450 * 14 * T / 100 for T gives T = $450 / ($450 * 0.14) = 7.14 years.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Interest Rate
When discussing financial matters, the interest rate is a crucial concept. It is the percentage of the principal amount that lenders charge borrowers for using their money, or that investors earn on their investments.

There are different types of interest rates, but in simple interest problems like this one, the percentage remains constant over time. This means the interest calculated each year is always the same as long as the principal stays unchanged.

The interest rate is generally expressed on an annual basis and can significantly impact the final amount accumulated through investments or owed on loans. A higher interest rate will cause the principal to grow faster when investing or increase the amount owed more quickly if borrowing.
Financial Algebra
Financial algebra involves using mathematical formulas and equations to solve monetary problems. It provides tools to make informed financial decisions.

In this exercise, the formula for simple interest, which is \( I = \frac{PRT}{100} \), plays a pivotal role. Here, \(I\) is the interest earned, \(P\) is the principal (initial amount), \(R\) is the rate of interest, and \(T\) is the time in years.

Understanding how to manipulate and rearrange this formula allows us to solve for any unknown variable, such as time in this case. This is a fundamental aspect of financial algebra, which requires basic algebraic skills to derive relations between different financial terms.
Doubling Money
The concept of doubling money is a common financial goal. It involves growing an investment so that the final amount equals twice the original principal.

With simple interest, doubling your money depends entirely on the variables defined in the interest formula.
  • First, determine the initial amount, or principal.
  • Next, apply an interest rate to see how much interest is earned over time.
  • Finally, calculate the time needed to earn interest equal to the principal itself.
If you want to double your money, a faster interest rate or patience for a longer period will achieve this goal.

In our example, the money will double in approximately 7.14 years at a 14% interest rate.
Time Calculation in Finance
Calculating time in finance, particularly in interest-based problems, involves understanding the relationship between principal, interest, and time. This exercise identifies the time it takes for an investment to reach a desired value using a specified interest rate.

Rearranging the simple interest formula can help us find how long it will take to achieve certain financial goals. For example, \( T = \frac{100I}{PR} \), where \(T\) is the time needed, \(I\) is the interest to be earned, \(P\) is the principal, and \(R\) is the rate.

By substituting the known values into this formula, such as in this exercise where \(P\) is \(450, \(R\) is 14%, and \(I\) is \)450 (for doubling), we can easily solve for \(T\) to find the duration in years.

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Most popular questions from this chapter

Kevin has \(x\) dollars in an account that pays 2.2\(\%\) interest, compounded quarterly. Express his balance after one quarter algebraically.

Rich has \(t\) dollars in his checking account. On June \(3,\) he deposited \(w_{1}, h,\) and \(v\) dollars, and cashed a check for \(k\) dollars. Write an algebraic expression that represents the amount of money in his account after the transactions.

On May 29, Rocky had an opening balance of x dollars in an account that pays 3% interest, compounded daily. He deposits y dollars. Express his ending balance on May 30 algebraically.

Ryan deposits \(\$ 775\) in an account that pays 4.24\(\%\) simple interest for four years. Brian deposits \(\$ 775\) in an account that pays 4.24\(\%\) simple interest for one year. a. What is Ryan’s interest after the four years? b. What is Ryan’s balance after four years? c. How much interest did Ryan’s account earn the first year? d. How much interest did Ryan’s account earn the fourth year? e. What is Brian’s interest after the first year? f. What is Brian’s balance after the first year? g. Suppose Brian withdraws all of the principal and interest after the first year and deposits it into another one-year account at the same rate, what is his interest for the second year? Round to the nearest cent. h. Compare the interest Brian earns with the interest Ryan earns for the second year. Who earned more interest? Explain.

Sydney invests \(\$ 100\) every month into an account that pays 5\(\%\) annual interest, compounded monthly. Benny invests \(\$ 80\) every month into an account that pays 8\(\%\) annual interest rate, compounded monthly. a. Determine the amount in Sydney’s account after 10 years. b. Determine the amount in Benny’s account after 10 years. c. Who had more money in the account after 10 years? d. Determine the amount in Sydney’s account after 20 years. e. Determine the amount in Benny’s account after 20 years. f. Who had more money in the account after 20 years? g. Write the future value function for Sydney’s account. h. Write the future value function for Benny’s account. i. Graph Benny and Sydney’s future value function on the same axes. j. Explain what the graph indicates.

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