Solving Percent Word Problems
Completion requirements
View
Percent problems are also a common type of algebra word problem which often come up when dealing with price mark-ups, sale prices, or calculating tips at restaurants. Read the examples of how to calculate percent from fractions and how to translate percent word problems into equations. Pay attention to the formula for finding the percent of change since we use this formula frequently to determine sale prices.
The Percent Equation
Percent problems are also a common type of algebra word problem which often come up when dealing with price mark-ups, sale prices, or calculating tips at restaurants. Read the examples of how to calculate percent from fractions and how to translate percent word problems into equations. Pay attention to the formula for finding the percent of change since we use this formula frequently to determine sale prices.
\(part = \% \ rate \times base\)
The key words in a percent equation will help you translate it into a correct algebraic equation. Remember the equal sign symbolizes the word "is" and the multiplication symbol symbolizes the word "of".
Example 1: Find 30% of 85.
Solution: You are asked to find the part of 85 that is 30%. First, translate into an equation.
\(n=30\% \times 85\)
Convert the percent to a decimal and simplify.
\( \begin{align*}n & =0.30 \times 85 \\ n & =25.5\end{align*}\)
Example 2: 50 is 15% of what number?
Solution: Translate into an equation.
\( 50 = 15\% \times w\)
Rewrite the percent as a decimal and solve.
\( \begin{align*}50 & = 0.15 \times w \\ \frac{50}{0.15} & = \frac{0.15 \times w}{0.15} \\ 333 \frac{1}{3} & = w\end{align*}\)