Pre-Algebra : Word Problems with One Unknown

Study concepts, example questions & explanations for Pre-Algebra

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Example Questions

Example Question #21 : Word Problems

Mike and his 2 brothers decided to buy a new video game console. If Mike and his brothers each paid $49, how much did the video game console cost?

Possible Answers:

$145

$155

$147

$137

$98

Correct answer:

$147

Explanation:

To solve this simple word problem, we need to understand what it is saying. The problem tells us that Mike and his brothers (three people in all) paid $49 apiece for a video game console. This means we need to multiply what each person paid by the number of people:

The total cost of the video game console was $147.

Example Question #22 : Word Problems

Choose the equation that will solve Amanda's scenario.

Amanda has  bracelets she made that she plans to share with her friends. She wants to keep  to give to her cousins. How many bracelets can she give to her friends?

Possible Answers:

Correct answer:

Explanation:

 is the correct answer to this question.

Amanda originally has  bracelets, so this is the number with which we begin.

Amanda is losing bracelets, so it is a subtraction problem.

Since the number we are solving for is the number of bracelets Amanda can give away,  is placed after the subtraction sign.

The number of bracelets that Amanda needs to finish with is , so the equation is set to equal .

Example Question #23 : Word Problems

Create an equation to solve the scenario.

Alex is the star player on his basketball team. For every basket he makes, his team receives  points. Alex scored  points in a game. How many baskets did he make?

Possible Answers:

Correct answer:

Explanation:

The correct answer to the question is 

The number of points that Alex scored is , so set the equation equal to .

The unknown number that we are looking for is the number of baskets, so set  equal to this.

Since each basket is worth  points, multiply  by .

The final equation comes out to be 

Example Question #21 : Word Problems With One Unknown

Create an equation to solve the scenario.

Megan needs  dollars to buy a new pair of jeans. She received  dollars from her grandmother for her birthday. Megan needs to figure out how much more she needs to save before she can buy the jeans.

Possible Answers:

Correct answer:

Explanation:

 is the correct answer to this question.

Megan originally has  dollars, so this is the number we begin with.

Megan needs to gain money, so this is an addition problem.

Since the number we are solving for is the amount of money that Megan needs to save,  is placed after the addition sign.

The amount of money that Megan needs to save is  dollars, so this is the number we set the equation equal to.

Example Question #25 : Word Problems

Create an equation for the scenario.

Lauren has  dollars. She wants to buy necklaces that cost  dollars each. How many necklaces is she able to buy?

Possible Answers:

Correct answer:

Explanation:

 is the correct answer to this question.

The amount of money that Lauren has is  dollars, so set the equation equal to .

On the opposite side of the equation, we solve for the unknown.

The unknown number that we are looking for is the number of necklaces she can buy, so set  equal to this.

Since each necklace costs  dollars, multiply  by
 

Example Question #22 : Word Problems

Ian and his two friends bought a pizza. They divided the pizza into twelve slices. If divided evenly, how many slices can Ian eat? 

Possible Answers:

Correct answer:

Explanation:

The problem is asking you to divide 12 into three parts.

We divide 12 by 3. By factoring 12 we see that the 3's cancel and we are left with 4.

 

Example Question #23 : Word Problems

Sally's Mom gave Sally  to go buy cookies at the store. If each cookie costs , how many cookies can Sally's  buy? 

Possible Answers:

Correct answer:

Explanation:

The question is asking you to divide the $20 by the cost of one cookie.

In this problem each cookie costs $2. 

Therefore, with $20 Sally can buy 10 cookies.

Example Question #27 : Word Problems

Matt was  years old in . How old is Matt in ?

Possible Answers:

Correct answer:

Explanation:

The question is asking you to add 7 years to Matt's age because .

Adding his age from 2000 to the number of years that have past from 2000 to 2007 we get his new age. 

Example Question #24 : Word Problems

Adam bought  pieces of candy at lunch. By dinner, Adam only had  pieces left. How many pieces did Adam eat?

Possible Answers:

Correct answer:

Explanation:

The question is asking you to subtract the 5 pieces leftover from the original amount of 20. 

Example Question #25 : Word Problems

Joe is traveling by car and his average speed is . If his destination is  away, how many hours will it take Joe to arrive if he travels his average speed?

Possible Answers:

Correct answer:

Explanation:

You are given two knowns; the rate of travel is , and the distance Joe needs to travel is . To find how long it takes Joe to get to his destination, we can set up a simple algebraic expression. Let  stand for our unknown travel time:

   

To solve for , divide both sides by 

 

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