Algebra Word Problem Interest Problems

The video tutorial covers the concept of interest, focusing on simple interest calculations. It explains how interest is calculated using the principal, rate, and time, and provides examples of solving word problems involving investments with different interest rates. The tutorial emphasizes understanding the relationship between principal, rate, and time, and how to set up equations to solve for unknowns in investment scenarios.

What is the formula for calculating simple interest?

• Interest = Principal x Rate x Time

• Interest = Principal + Rate + Time

• Interest = Principal / Rate / Time

• Interest = Principal - Rate - Time

In a word problem, if you invest $12,000 at two different rates and earn $760 in interest, what is the first step to solve for the amounts invested at each rate?

• Ignore the interest rates

• Set up an equation for total interest

• Calculate the average interest rate

• Divide the total investment equally

If Sally invests $7,000 at two different interest rates and earns $310 in interest, what equation would you set up to find the amounts invested?

• A / B = 7,000

• A x B = 7,000

• A - B = 7,000

• A + B = 7,000

In a problem where you invest twice as much in stocks as in bonds, what is the relationship between the amounts invested in stocks (S) and bonds (B)?

• S = B + 2

• S = B/2

• S = 2B

• S = B

If you have $1,300 less invested at 9% than at 5%, how would you express the amount invested at 9% in terms of the amount invested at 5%?

• A = B + 1,300

• A = B x 1,300

• A = B - 1,300

• A = 1,300 - B

What is the main difference in solving the final investment problem compared to the others?

• It does not involve interest rates

• It uses a different interest formula

• It requires only one equation

• It involves compounding interest

In the final problem, if you have $3,000 invested at 6%, how do you determine how much to invest at 4% to achieve a total interest of $372?

• Set up an equation for total interest

• Divide the total interest by 2

• Multiply the total interest by 2

• Ignore the interest rates

What is the purpose of using the simple interest formula in these problems?

• To find the time period

• To determine the principal amount

• To calculate monthly interest

• To illustrate the concept of interest growth

Why can't the simple interest formula be directly applied to real-life credit cards?

• Because they use a different currency

• Because they involve compounding interest

• Because they have no interest rates

• Because they are not investments

What is the key factor to consider when setting up equations for these interest problems?

• The number of investments

• The color of the money

• The type of bank account

• The total interest earned