A comprehensive guide to mastering the math concepts tested on the PSAT, including real-world applications and testing strategies.
A ratio compares two quantities. For example, if there are 2 apples and 3 oranges, the ratio of apples to oranges is \( 2:3 \).
A proportion is an equation that states two ratios are equal. For example, \( \frac{2}{3} = \frac{4}{6} \).
Percents are ratios out of 100. They're everywhere: discounts, grades, statistics! Knowing how to convert between fractions, decimals, and percents is super useful.
Set up proportions to solve for missing quantities, or use percent formulas to find parts, wholes, or percentages.
Think about shopping sales, calculating tax or tip, or comparing stats in sports—all use ratios and percents!
If 30% of a class of 20 students are absent, then \( 0.3 \times 20 = 6 \) students are absent.
If a recipe needs 2 cups of flour for every 3 cups of sugar, then for 6 cups of sugar you need \( 2 \times 2 = 4 \) cups of flour.
Ratios, proportions, and percents help you compare and relate quantities in everyday situations.