Linear Equations with Money - Basic Arithmetic

This is a simple interest rate problem, for which we use the formula:

Interest = P x r x t

P is the principal, or original loan amount; r is the annual interest rate; and t is the number of years in question.

In this problem we are given the interest ($100); the principal ($2,000); the interest rate (5%). We are asked to find t, the time in years it takes for $100 of interest to accumulate. We plug all these values into the formula and solve for t:

t is equal to 1 year. It will take 1 year for $100 of interest to accumulate.

1. Find the equation from this scenario:

Since Bobby makes $12 an hour, you know that your slope is 12 because his total pay will be the $12 multiplied by the number of hours he worked.

Add the $5 daily bonus Bobby makes, which is your y-intercept in this equation.

Total = $12(hours) + $5

2. Find his total pay for 5 hours using the above equation:

$65

To solve this problem, first you need to create a linear equation: .

Divide both sides by :

.

.

Now, Anne can't buy .462 lollipops, so you round off to Now you must calculate the money left over:

.

So, Anne bought lollipops and she has left over.

Create a linear equation to find your answer:

Since Jim makes 12 dollars per hour we can multiply 12 by the number of hours he worked. We then can multiply that number by the number of days he worked to get the total money earned.

Convert back into dollars, so you have .

In 4 weeks, Jamie will automatically be spending $300 on rent, so we will subtract this amount from whatever income Jamie makes.

In order to calculate her income, we will multiply $60 by 5, which equals $300.

Jamie makes $300 a week.

Then we will multiply this number by 4, since we are finding her net profit over 4 weeks. $300 times 4 equals $1200.

Lastly, we subtract her rent payment ($300) from her $1200 income, making her net profit $900.

First, we want to determine Bill's income this month, independent of his stipend. We calculate his income by multiplying $30 by how many days he worked in a month. In this case, he worked 10 days. Therefore, we multiply $30 by 10, which equals $300.

Since Bill also has a consistent monthly stipend of $500, we add his income of $300 to his stipend of $500, which totals $800.

To calculate how much money Samuel made this week, we will multiply how many cakes he made with how much profit he earns per cake. This week, Samuel made 25 cakes at $5 profit per cake, so we will multiply 25 by $5, which equals $125.

On top of this, we will add the $25 tip given to Samuel, which comes to a grand total of $150 earned this week.

Landry rides 4 rides at the carnival, which cost $2 each. To determine their total cost, we will multiply 4 by $2, which equals $8.

Then we need to add the initial cost of entering the carnival, which is also $8. Adding these together, we find that Landry spent $16 at the carnival.

To find the cost of the bowling outing for the Johnson family, we need to add the cost of the bowling lane with the cost of renting shoes. Each family member rents a pair of shoes, which cost $2 per pair. Since there are 5 members of the Johnson family, we will multiply 5 times $2, which equals $10.

Then we need to add the cost of renting one bowling lane, which is another $10. The Johnson family spent $20 at the bowling alley.

In this problem, we need to first determine how many seats have been sold. In order to do so, we need to divide the total amount of money received for the seats, $860, by the cost of each individual seat, $20. $860 divided by $20 equals 43.

Now we know that the concert hall has sold 43 seats. However, we are not done yet. We need to subtract 43 from the original number of available seats, 100, in order to find the amount of remaining seats. 100 minus 43 is 57, so there are 57 seats left to be sold.

To find Lacy's profit, we need to first determine how much money she made from simply selling her coffee. We know she sold 230 cups of coffee that cost $2 each, so we will multiply 230 by $2, which equals $460.

Now we need to subtract the amount she paid for the coffee beans originally, which was $100. $460 minus $100 equals $360.

This is Lacy's profit.

To begin solving this problem, we will first determine how much money Carly spent playing games at the arcade. Since she played 25 games at $0.50 each, we will multiply 25 by $0.50, which equals $12.50.

Then Carly had to pay her friend Blake $5 that she owed him, so we will add $5 to the $12.50 she already spent, which equals $17.50.

The last step is to subtract our total amount spent, $17.50 from her starting amount, $20. When we do this, we find that Carly had $2.50 remaining at the end of the day.

First we will determine how much money Jerry earned from selling hot dogs at the festival. To do this, we will multiply the number of hot dogs sold (300) by the cost of each hot dog ($4). This comes to a total of $1200 earned.

Now we need to subtract the $500 vendor fee from the total earned, bringing Jerry's profit to $700.

Samantha initially spends $50 on a haircut, and then an additional $12 on each service. Aside from the haircut, Samantha gets highlights, a shampoo and styling, which makes 3 services. We now will multiply the cost of each service ($12) by the number of services (3).

This equals $36, which we will add to the initial fee for the hair cut, $50. $36 plus $50 equals $86, the total cost of Samantha's hair cut and services.

First, we will multiply the cost of each dish ($6) with the number of dishes purchased (9).

Then we will add on the cost of the tip for the waiter, $30, which brings the total that Pete and his friends spent at the restaurant to $84.

To begin this problem, we need to isolate how much money Ike has to spend on toppings. In order to do this, we will first subtract the initial cost of the sundae ($3.50) from the amount of money that Ike has ($7.00).

Now, we need to see how many $0.50 toppings Ike can afford with $3.50. To do this, we will divide $3.50 by $0.50, which equals 7.

Therefore, Ike can afford to purchase 7 toppings for his sundae.

To figure out how many minutes Mark can wash his car, we must understand the relationship between the total cost of a car wash and the length of the car wash.

With every car wash, a fee of is needed to dry the vehicle, so Mark will only have remaining to spend on washing his car. If it costs per minute to wash his car, we merely need to divide by to determine the number of minutes that Mark can wash his car:

Therefore, with Mark's , he can wash his car for minutes.