Suppose that Saul has money in a savings account that pays him interest of 5% per year on the account balance. Now, Saul takes out $50 a month for various frivolities, and his mother secretly deposits $240 every 6 months into his savings account. Assuming that interest is paid and money is deposited and withdrawn from the account in a continuous fashion, the balance B = B(t) (in dollars) remaining in Saul's savings account at time t (in months) is best modeled by the differential equation: A. at dB = 0.05B-10 B. dt C. dt 器 D. dt = dB E. dt 0.05B-10 12 0.05B 12 = -- 190 0.05B 12 - 50 = 0.05B-120

Calculus: Early Transcendentals
8th Edition
ISBN:9781285741550
Author:James Stewart
Publisher:James Stewart
Chapter1: Functions And Models
Section: Chapter Questions
Problem 1RCC: (a) What is a function? What are its domain and range? (b) What is the graph of a function? (c) How...
icon
Related questions
Question
### Modeling a Savings Account with Continuous Interest and Transactions

**Context:**
Suppose that Saul has money in a savings account that pays him an interest of 5% per year on the account balance. Now, Saul takes out $50 a month for various frivolities, and his mother secretly deposits $240 every 6 months into his savings account. Assuming that interest is paid and money is deposited and withdrawn from the account in a continuous fashion, the balance \( B = B(t) \) (in dollars) remaining in Saul's savings account at time \( t \) (in months) is best modeled by the differential equation:

To determine the most accurate model, we are presented with the following options of differential equations:

**Options:**

A. \[ \frac{dB}{dt} = \frac{0.05B}{12} - 10 \]

B. \[ \frac{dB}{dt} = 0.05B - 10 \]

C. \[ \frac{dB}{dt} = \frac{0.05B}{12} - 190 \]

D. \[ \frac{dB}{dt} = \frac{0.05B}{12} - 50 \]

E. \[ \frac{dB}{dt} = 0.05B - 120 \]

### Explanation of Differential Equations:

1. **Interest Calculation:**
   - The interest rate of 5% per year is equivalent to a monthly interest rate of \( \frac{0.05}{12} \), since there are 12 months in a year.

2. **Withdrawals:**
   - Saul takes out \( $50 \) every month, which affects the balance negatively.

### Examination of Each Option:

- **Option A:**
  \[ \frac{dB}{dt} = \frac{0.05B}{12} - 10 \]
  - **Interest Component:** \( \frac{0.05B}{12} \), which represents monthly interest.
  - **Withdrawal Component:** \( 10 \), representing the conversion of \( $50 \) monthly withdrawals to \( \$ \) per month (divided incorrectly, should consider full 50).

- **Option B:**
  \[ \frac{dB}{dt} = 0.05B - 10 \]
  - **Interest Component:** \(
Transcribed Image Text:### Modeling a Savings Account with Continuous Interest and Transactions **Context:** Suppose that Saul has money in a savings account that pays him an interest of 5% per year on the account balance. Now, Saul takes out $50 a month for various frivolities, and his mother secretly deposits $240 every 6 months into his savings account. Assuming that interest is paid and money is deposited and withdrawn from the account in a continuous fashion, the balance \( B = B(t) \) (in dollars) remaining in Saul's savings account at time \( t \) (in months) is best modeled by the differential equation: To determine the most accurate model, we are presented with the following options of differential equations: **Options:** A. \[ \frac{dB}{dt} = \frac{0.05B}{12} - 10 \] B. \[ \frac{dB}{dt} = 0.05B - 10 \] C. \[ \frac{dB}{dt} = \frac{0.05B}{12} - 190 \] D. \[ \frac{dB}{dt} = \frac{0.05B}{12} - 50 \] E. \[ \frac{dB}{dt} = 0.05B - 120 \] ### Explanation of Differential Equations: 1. **Interest Calculation:** - The interest rate of 5% per year is equivalent to a monthly interest rate of \( \frac{0.05}{12} \), since there are 12 months in a year. 2. **Withdrawals:** - Saul takes out \( $50 \) every month, which affects the balance negatively. ### Examination of Each Option: - **Option A:** \[ \frac{dB}{dt} = \frac{0.05B}{12} - 10 \] - **Interest Component:** \( \frac{0.05B}{12} \), which represents monthly interest. - **Withdrawal Component:** \( 10 \), representing the conversion of \( $50 \) monthly withdrawals to \( \$ \) per month (divided incorrectly, should consider full 50). - **Option B:** \[ \frac{dB}{dt} = 0.05B - 10 \] - **Interest Component:** \(
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 2 images

Blurred answer
Similar questions
Recommended textbooks for you
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781285741550
Author:
James Stewart
Publisher:
Cengage Learning
Thomas' Calculus (14th Edition)
Thomas' Calculus (14th Edition)
Calculus
ISBN:
9780134438986
Author:
Joel R. Hass, Christopher E. Heil, Maurice D. Weir
Publisher:
PEARSON
Calculus: Early Transcendentals (3rd Edition)
Calculus: Early Transcendentals (3rd Edition)
Calculus
ISBN:
9780134763644
Author:
William L. Briggs, Lyle Cochran, Bernard Gillett, Eric Schulz
Publisher:
PEARSON
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781319050740
Author:
Jon Rogawski, Colin Adams, Robert Franzosa
Publisher:
W. H. Freeman
Precalculus
Precalculus
Calculus
ISBN:
9780135189405
Author:
Michael Sullivan
Publisher:
PEARSON
Calculus: Early Transcendental Functions
Calculus: Early Transcendental Functions
Calculus
ISBN:
9781337552516
Author:
Ron Larson, Bruce H. Edwards
Publisher:
Cengage Learning