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§ 5.3A. Solving Percent Problems Using Equations. Percent Problems into Equations. To solve a percent problem, we express it as an equation with an unknown quantity. The following table is helpful when translating from a percent problem to an equation. Percent Problems into Equations.
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§ 5.3A Solving Percent Problems Using Equations
Percent Problems into Equations To solve a percent problem, we express it as an equation with an unknown quantity. The following table is helpful when translating from a percent problem to an equation.
Percent Problems into Equations Example: Translate into an equation. What is 9% of 65? n = 9% 65 Example: Translate into an equation. 24 is what percent of 144? 24 = n 144
Solving a Percent Problem A percent problem has three different parts. amount = percent base Any one of the three quantities may be unknown. 1. When we do not know the amount: n = 10% 500 2. When we do not know the base: 50 = 10% n 3. When we do not know the percent: 50 = n 500
n = 9% 65 n = (0.09) (65) n = 5.85 Solving a Percent Problem: Amount Unknown amount = percent base Example: What is 9% of 65? 5.85 is 9% of 65.
36 = 6% n Solving a Percent Problem: Base Unknown amount = percent base Example: 36 is 6% of what? 36 = 0.06n 36 is 6% of 600.
24 = n 144 Solving a Percent Problem: Percent Unknown amount = percent base Example: 24 is what percent of 144?
§ 5.3B Solving Percent Problems Using Proportions
The Parts of a Percent Proportion Proportions are another way to solve a percent problem. To use this proportion, we need to find the amount, base, and percent number in a word problem.
The Parts of a Percent Proportion 10% of 500 is 50. p is the percent number. The amount, a, is the part compared to the whole. The base, b, is the entire quantity.
The Parts of a Percent Proportion Example: Identify the amount, base, and percent number. What is 9% of 65? The base usually follows the word of. b = 65 The amount, a, is unknown. a = the amount (unknown) The value of p is 9. p = 9 24 is what percent of 144? The base usually follows the word of. b = 144 The amount is 24. a = 24 The value of p is unknown. p = the percent (unknown)
p = 9 a = unknown b = 65 Solving a Percent Problem: Amount Unknown Example: What is 9% of 65? Cross multiply. Divide both sides by 100. Simplify. 5.85 is 9% of 65.
p = 6 a = 36 b = unknown Solving a Percent Problem: Base Unknown Example: 36 is 6% of what? Cross multiply. Divide both sides by 6. Simplify. 36 is 6% of 600.
p = unknown a = 24 b = 144 Solving a Percent Problem: Percent Unknown Example: 24 is what percent of 144? Cross multiply. Divide both sides by 144. Simplify.