1. Base: The number that represents the whole or 100%.
Amount: The number that represents part of a whole.
Percent: The number that defines what part the amount is of the whole.
B = Base
A = Amount
P = percent
Percent Equation: Percent  Base = Amount or P  B = A
Procedure: Solving Percent Problems using a Percent Equation:
1. Percents must be converted to a decimal or a fraction.
2. “what percent”: percent is unknown
“of what number”: base is unknown
“is what number”: amount is unknown
3. Substitute the values given into the percent equation. One of the values
will not be given; either P, B, or A.
4. Solve the equation. If finding a percent, convert the decimal to a percent.
Example % of what number is 60.
Solution:
1. List the given information.
P=0.75
B=?
A = 60
Equation:
P  B = A
2. Substitute the information into the equation and solve.
0.75  B = 60
Your Turn Problem #1
20% of what number is 18?
Answer: 90
B = 80
75% of 80 is 60.

2. Example 2. 105 is what percent of 140?
1. List the given information.
Solution:
P=?
B=140
A = 105
Equation:
P  B = A
2. Substitute the information into the equation and solve.
P  140 = 105
P = 0.75
Division not shown
Your Turn Problem #2
81 is what percent of 540?
P = 75%
105 is 75% of 140.
Answer: 15%
Example % of 28 is what number?
Solution:
P=0.14
B=28
A =?
Equation:
P  B = A
1. List the given information.
0.14 28 = A
2. Substitute the information into the equation and solve.
14% of 28 is 3.92.
A = 3.92
Multiplication not shown
Your Turn Problem #3
5% of is what number?
Answer: 9.01

3. Solution: P = 2/9 B=? A =46 Equation: P  B = A B = 207
1. P must be written as a decimal or a fraction.
2. List the given information.
P = 2/9
B=?
A =46
Equation:
P  B = A
3. Substitute the information into the equation and solve. To solve an equation with a fraction in front of the variable, multiply both sides by its reciprocal on both sides.
B = 207
22 2/9% of 207 is 46.
Your Turn Problem #4
Answer: 174

4. Solving Percent Problems using Proportions
This is another method for solving percent problems.
1. The percent will not need to be converted to a decimal or a fraction (because of the 100 in the formula).
2. Substitute the values given in into the formula and solve the equation.
Example % of what number is 6975?
Solution:
P = 31
B= ?
A = 6975
1. List the given information.
2. Substitute the information into the formula and solve.
Your Turn Problem #5
548 is what percent of 2740?
Answer: 20%
The End
B.R.
6-6-08
31B =
B = 22,500