1. Solving Percent Equations
Chapter 8.4
Solving Percent Equations

2. Objectives I will find what percent one number is of another.
I will solve a percent equation

3. Percent Equations
The statement “a is p percent of b” is equivalent to the equation:
In this equation, b is the base and a is the number that is compared to the base.

4. Finding Percents
You got 17 points on a 20-point quiz. You can find the percent, p, that you got correct as follows…
Write percent equation.
Divide to obtain decimal form.
Multiply both sides by 100
You got 85% correct.

5. Give it a try! 
Suppose you earned 15 points on a 20-point quiz. Calculate the percent correct.
75%

6. Finding Percents
On a 50-point quiz, you got 48 points plus 5 bonus points. You can find the percent p that you got correct as follows.
Write percent equation.
Divide to obtain decimal form.
Multiply both sides by 100
You got 106% correct.

7. Solving percent equations
In a survey of 250 people, 82% said they prefer blue jeans to any other color of jeans. How many preferred blue jeans?
100a = 20,500
a = 205
So 205 people said they prefer blue jeans
Write percent equation
Cross multiply to
Write an equation
Solve for a

8. Problem solving with percents
You paid $26.49, which is 75% of the full price for a sweater. What is the full price?
2649 = 75 b
$35.32 = b
The full price of the sweater is $35.32
Write percent equation
Cross multiply to
write an equation
Solve for b

9. Summary of the three basic types of percent problems
What is p percent of b?
a is p percent of what?
a is what percent of b?
Solve for a
Solve for b
Solve for p