Ratios, Rates & Proportions
Solve problems involving ratios, unit rates, and proportional relationships.
Practice Problems
Boys:girls = 3:5, 24 boys
180 miles in 3 hours, find distance in 5 hours
Pro Tips & Shortcuts
SAT Tip: Ratios appear in 10-15% of SAT Math questions, often in word problems.
SAT Tip: Unit rates make comparisons easier. Always convert to unit rate when comparing.
SAT Tip: Cross-multiplication is the fastest method for solving proportions on the SAT.
SAT Tip: When given one quantity and a ratio, set up a proportion to find the other.
SAT Tip: For rate problems, finding the unit rate first often simplifies the problem.
To find actual quantities from a ratio, multiply each part by the same number.
Divide to find "per one unit": $6 for 3 items = $6÷3 = $2 per item.
Set up proportion with unknown on top left for easier solving.
Check: 24:40 = 3:5? Yes, both simplify to 3:5.
Distance = Rate × Time. This is the fundamental rate formula.