Word Problems on Equivalent Ratios
Problem 1:
A fruit basket has 3 apples for every 2 bananas. If there are 12 apples, how many bananas should there be?
Solution:
Original ratio = 3:2.
Apples = 12, which is 3 × 4.
Multiply bananas (2) × 4 = 8.
So, there are 8 bananas.
Problem 2:
A car consumes 5 liters of fuel to travel 40 km. How much fuel is needed for 100 km?
Solution:
Ratio fuel:distance = 5:40 = 1:8.
For 100 km → 100 ÷ 8 = 12.5 liters.
So, 12.5 liters are required.
Problem 3:
A teacher distributes pencils in a ratio of 2:5 (boys:girls). If 20 pencils are given to boys, how many go to girls?
Solution:
Ratio boys:girls = 2:5.
Boys = 20 → 2 × 10.
Multiply girls (5) × 10 = 50.
So, 50 pencils are given to girls.
Why Equivalent Ratios Matter
Equivalent ratios are critical because they:
Form the basis of proportional reasoning in mathematics.
Simplify real-world problem solving in cooking, construction, budgeting, and travel.
Help in scaling recipes, maps, and models.
Provide a foundation for understanding fractions, percentages, and algebra.
Common Mistakes to Avoid
Changing only one number — You must multiply or divide both terms by the same factor.
Example: 2:3 → 4:3 (❌ wrong).
Mixing up order — 2:3 is not equivalent to 3:2.
Always maintain the order.
Forgetting to simplify — Ratios should often be reduced to lowest terms for clarity.
Example: 10:20 simplifies to 1:2.
Conclusion
Equivalent ratios are one of the cornerstones of mathematics. They allow us to represent the same relationship in multiple forms, making it easier to compare, calculate, and apply proportional reasoning. By multiplying or dividing both terms of a ratio by the same number, we can generate new equivalent ratios that are useful in solving word problems and handling real-life situations.