# Chapter 20

Traditional story problems sometimes have a less-than-desirable reputation. You probably won't ever need to know how old a person is if he's twice as old as another person was 16 years ago. But the structure of these story problems and the discipline of working out the logic and mathematics go far to improve mathematical agility. The problems in this chapter are pretty traditional and classic in the mathematics classroom.

## The Problems You'll Work On

The traditional story problems you'll work on in this chapter include the following scenarios:

• Determining a person's age with respect to others and the passage of time
• Figuring out how much work a person is doing and how long it will take to complete the project
• Computing how much of one liquid to add to another to get the desired mixture
• Counting pennies, nickels, and dimes without ever touching the money
• Regrouping and commuting values for ease and accuracy
• Determining one or more numbers in a list of consecutive integers

## What to Watch Out For

Here are some ways to ensure that you're correctly solving the problems in this chapter:

• Creating an equation or expression that represents what's going on in the problem
• Always letting variables represent numbers, not people or things
• Taking advantage of drawing pictures to help create the correct equation
• Solving the equations correctly, using the rules of equations
• Checking your answers to see whether they fit the situation and make sense ...

Get Algebra I: 1,001 Practice Problems For Dummies now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.