# GED Math : Single-Variable Algebra

## Example Questions

### Example Question #18 : Word Problems In Algebra

A writer make  dollars of profit per book sold.  The printing run of a lot of books cost  dollars.  How many books must the author sell before the book becomes profitable?

Explanation:

This question could be set up like an equation as follows:

The variable  indicates the number of books that would have to be sold.  This comes out to:

Now, don't be tricked!  You can't sell partial books.  Thus, you will need to sell  books in order to turn a profit.  If you only sell , you will not have sold enough to make a profit.

### Example Question #20 : Word Problems In Algebra

An author writes a book that sells for  dollars.  He has  published at a cost of  dollars per book.  How many books must he sell before his profit is at least  dollars per book?

books

books

books

books

books

books

Explanation:

This question is a bit hard.  You need to think it out step by step.  First, you could write an equation like this:

This represents the idea of trying to calculate when the profit per book will be three dollars.  Now, we know that profit is equal to:

Thus, you can rewrite your equation:

Now, the original cost is calculated by multiplying  by .  This is the same as .  The sales amount is just , where  indicates the total number of books sold.  This will also be the total for  in your equation.  Thus, you can write out the following equation:

Now, just solve for :

However, you will need to sell one more book than .  (That would be just a little too insufficient.)  Thus, the answer is .

### Example Question #151 : Algebra

Timmy works at a fast food chain retail store five days a week, eight hours a day. Suppose it costs him $2.00 everyday to drive to and from work. He makes$10.00 per hour. How much will Timmy have at the end of the week, before applicable taxes?

Explanation:

Timmy makes ten dollars per hour for eight hours.

For five days:

Timmy also will pay  for the week to get to work and back.

Subtract his expense from his earnings for the week.

Timmy will have  by the end of the week.

### Example Question #21 : Word Problems In Algebra

Jessica placed  in a savings account that has an interest rate of . If the interest that was generated was , how many months was the money deposited?

Explanation:

Recall the formula for calculating the interest:

, where  is the amount of interest generated,  is the principle (initial deposit),  is the interest rate, and  is the time in years.

Since the question asks for a length of time, we will need to solve for .

Plug in the given information and solve for .

Recall that  is given in years. However, the question wants the number of months the money was deposited for. Thus, multiply by  to get the number of months.

The money was deposited for  months.

If Richard works for 5 hours per day earning $10 per hour for five days a week, how much will he have after 2 weeks? Possible Answers: Correct answer: Explanation: Calculate how much Richard will earn per day. For five hours at an hourly wage of : He will work five days per week. At the end of 2 week period, Richard will have worked a total of 10 days. Multiply the per day with 10 to get the total amount. The answer is: ### Example Question #22 : Word Problems In Algebra Joseph can spend up to on video games this month. If each video game costs , which of the following represents the conditions of Joseph's purchase? Possible Answers: Correct answer: Explanation: Because the question states that Joseph can spend up to , we know that we will be using a less than or equal to sign. We cannot use an equal sign because that means Joseph will be spending exactly . Since each video game costs , that means if Joseph buys number of games, he will spend . Thus, the conditions of his purchase can be illustrated by . ### Example Question #25 : Word Problems In Algebra A computer that is on sale for off costs . What was the original price of the computer? Possible Answers: Correct answer: Explanation: Let be the original cost of the computer. Since we have taken off, can represent the amount that is taken off. We can then write the following equation: Now solve for . ### Example Question #153 : Algebra The fare for a taxi meter is calculated as follows: Each fare will have an initial charge to pick someone up. Then, is added for each mile driven. Which of the following expressions illustrates the taxi fare if an individual took a trip miles long? Possible Answers: Correct answer: Explanation: First, calculate the cost for the miles driven. Since the rider will be charged for every mile driven, we can write the expression to illustrate the total mileage cost. Next, since the problem states that will be a one-time charge on the fare, we can then write the following expression to illustrate the total cost of a taxi ride of miles: ### Example Question #151 : Single Variable Algebra Sixty-four coins, all dimes and quarters, total$8.95. How many quarters are there?

Explanation:

Let  be the number of quarters. Then there are  dimes.

An equation can be set up and solved for  for the amount of money in dollars:

### Example Question #154 : Algebra

Ten less than three times a number squared is 182. What is the number?