/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 6 A bank deposit paying simple int... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

A bank deposit paying simple interest at the rate of \(5 \%\) year grew to a sum of \(\$ 3100\) in \(10 \mathrm{mo}\). Find the principal.

Short Answer

Expert verified
The principal amount of the bank deposit is approximately \( \$2300 \).

Step by step solution

01

Convert Annual Interest Rate to Monthly Interest Rate

The given interest rate is 5% per year, and we need to convert it to a monthly interest rate since the given time period is in months. Divide the annual interest rate by 12 to get the monthly interest rate: \(Monthly Interest Rate = \frac{Annual Interest Rate}{12} = \frac{5}{12} \% \)
02

Convert 10 Months to a Fraction of a Year

Now, we need to convert the time period (10 months) to a fraction of the year. To do this, divide the number of months (10) by the total months in a year (12): \(Fraction of a Year = \frac{10}{12} \)
03

Calculate the Interest Amount Using Simple Interest Formula

Now, we will use the formula for simple interest to find the interest amount: \( Interest = Principal × Rate × Time \) We know the total amount ($3100) and need to find the interest amount. To do this, we will find the interest amount which, when added to the principal, results in the total amount: \(3100 = Principal + Principal \times \frac{5}{12 \%} \times \frac{10}{12} \) Simplify the equation: \(3100 = Principal × (1 + \frac{5}{12} \times \frac{10}{12}) \) Now, let's solve for the Principal.
04

Solve for the Principal Amount

Solve for the Principal: \(Principal = \frac{3100}{1 + \frac{5}{12} \times \frac{10}{12}} \) Calculate the denominator: \(1 + \frac{5}{12} \times \frac{10}{12} = 1 + \frac{50}{144} = \frac{194}{144} \) Now, divide the total amount by the denominator: \(Principal = \frac{3100}{\frac{194}{144}} = 3100 \times \frac{144}{194} \) Calculate the principal amount: \(Principal ≈ \$2300 \) So, the principal amount of the bank deposit is approximately $2300.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

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

Interest Rate Conversion
Understanding Interest Rate Conversion is vital when dealing with different time periods relative to the standard annual rate. In the context of the provided exercise, we converted an annual interest rate to a monthly interest rate because the transaction period was less than one year.

Why is this important? Conversion is essential for accurate calculations. Interest rates are typically annual, but financial transactions can occur over various time frames – monthly, quarterly, or daily. Without conversion, assessments on interest would be incorrect, and financial decisions based on such assessments would be flawed.

How to Convert Rates: The formula for converting an annual interest rate to a monthly interest rate involves dividing the annual rate by 12 (the number of months in a year). The conversion is represented mathematically as:\[\begin{equation}Monthly Interest Rate = \frac{Annual Interest Rate}{12}\end{equation}\]In our exercise, this meant dividing the 5% annual rate by 12, resulting in a monthly rate of approximately 0.417%. This conversion ensures that when we calculate interest for a period that is not a full year, we are utilizing an appropriate rate for the time frame in question.
Time Value of Money
The Time Value of Money (TVM) is a fundamental financial concept stating that money available today is worth more than the same amount in the future due to its potential earning capacity. This core principle is the basis for the concept of interest.

In relation to simple interest and our exercise, the time value of money illustrates why financial institutions compensate depositors with interest over time. The present value of money is adjusted based on interest that could be earned over a specified time. If we have \(100 now and save it in an account that earns 5% annually, in one year, we'd expect it to grow to \)105. This potential for growth affects both how we value future cash flows and the interest rates set by banks and lenders.

Effect of Time on Interest: The longer the time period, the more interest accrues, assuming all other factors are held constant. However, when the time period is not in complete years (such as 10 months in the exercise), the interest earned must be prorated accordingly. For our exercise, converting 10 months to a fraction of a year (10/12) is critical for determining the applicable interest over the time period the money is deposited.
Simple Interest Formula
The Simple Interest Formula is a quick way to calculate the interest charge on a loan or the interest earned on a deposit.

Formula: The formula for calculating simple interest is:\[\begin{equation}Interest = Principal \times Rate \times Time\end{equation}\]In our exercise, we determine how much interest is accumulated over 10 months on a bank deposit, and then back out the original principal from the total amount. It is crucial to use the converted monthly interest rate and the time expressed in years.

Here's another look at the process:- We know the future value of the deposit ($3100).- The interest rate is converted to a monthly percentage, and the time is adjusted to a fraction of a year.- We plug these values along with the future value into the formula and solve for the principal.This methodological approach is important because simple interest is directly proportional to the time the money is borrowed or deposited. Therefore, a longer time period means more interest is earned or paid. Conversely, a shorter period means less interest. In the exercise, by knowing the final amount and the time involved, we calculated back to find the original principal – which is the sum initially deposited before any interest was added.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

FINANCING A CAR The price of a new car is \(\$ 16,000\). Assume that an individual makes a down payment of \(25 \%\) toward the purchase of the car and secures financing for the balance at the rate of \(10 \% /\) year compounded monthly. a. What monthly payment will she be required to make if the car is financed over a period of \(36 \mathrm{mo}\) ? Over a period of \(48 \mathrm{mo}\) ? b. What will the interest charges be if she elects the 36 -mo plan? The 48 -mo plan?

A culture of a certain bacteria is known to double in number every \(3 \mathrm{hr}\). If the culture has an initial count of 20 , what will be the population of the culture at the end of \(24 \mathrm{hr}\) ?

Mitchell has been given the option of either paying his \(\$ 300\) bill now or settling it for \(\$ 306\) after 1 mo ( 30 days). If he chooses to pay after 1 mo, find the simple interest rate at which he would be charged.

FINANGING CoLLEGE EXPENSES Yumi's grandparents presented her with a gift of \(\$ 20,000\) when she was 10 yr old to be used for her college education. Over the next \(7 \mathrm{yr}\), until she turned 17 , Yumi's parents had invested her money in a tax-free account that had yielded interest at the rate of 5.5\%/year compounded monthly. Upon turning 17 , Yumi now plans to withdraw her funds in equal annual installments over the next \(4 \mathrm{yr}\), starting at age \(18 .\) If the college fund is expected to earn interest at the rate of \(6 \% /\) year, compounded annually, what will be the size of each installment?

Today a typical family of four spends \(\$ 600 /\) month for food. If inflation occurs at the rate of \(3 \% /\) year over the next \(6 \mathrm{yr}\), how much should the typical family of four expect to spend for food 6 yr from now?

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.