Ratio Proportion Scale Practice Problems with Solutions

Master ratio, proportion, and scale problems with step-by-step practice exercises. Learn equivalent ratios, direct/inverse proportionality, and scale calculations.

📚Practice Ratio, Proportion, and Scale Problems
  • Solve ratio problems with part-to-whole and part-to-part relationships
  • Find equivalent ratios using simplification and multiplication methods
  • Calculate missing values in proportions using cross multiplication
  • Distinguish between direct and inverse proportionality in real-world scenarios
  • Apply scale factors to solve map and drawing problems
  • Distribute quantities according to given ratios step-by-step

Understanding Ratio, Proportion and Scale

Complete explanation with examples

Summary

Ratio, Proportion, and Scale

The ratio between terms describes how many times greater or smaller a certain magnitude is than the other.

Proportion is a constant relationship or ratio between different magnitudes.

Scale is the proportionality between the real dimensions of something and those of the scheme that represents it.

Detailed explanation

Practice Ratio, Proportion and Scale

Test your knowledge with 3 quizzes

How many times longer is the radius of the red circle than the radius of the blue circle?

210

Examples with solutions for Ratio, Proportion and Scale

Step-by-step solutions included
Exercise #1

If there are 18 balls in a box of which 23 \frac{2}{3} are white:

How many white balls are there in the box in total?

Step-by-Step Solution

To solve this problem, we will determine the number of white balls in the box using a fraction of the total number of balls.

We are given the total number of balls in the box as 18, and we know that 23 \frac{2}{3} of these balls are white. To find the number of white balls, we follow these steps:

  • Step 1: Identify the total quantity, which is 18 balls.
  • Step 2: Use the given fraction 23 \frac{2}{3} to find the number of white balls.
  • Step 3: Multiply the total number of balls by the fraction of white balls: 18×23 18 \times \frac{2}{3} .

Perform the calculation:

18×23=18×0.6667=12 18 \times \frac{2}{3} = 18 \times 0.6667 = 12

Alternatively, calculate directly using fractions:

18×23=18×23=363=12 18 \times \frac{2}{3} = \frac{18 \times 2}{3} = \frac{36}{3} = 12

Thus, the total number of white balls in the box is 12.

Therefore, the correct answer is choice 12.

Answer:

12

Video Solution
Exercise #2

In a box there are 28 balls, 14 \frac{1}{4} of which are orange.

How many orange balls are there in the box in total?

Step-by-Step Solution

To solve this problem, we'll determine the number of orange balls by calculating the fraction of the total number of balls:

  • Step 1: Identify the total number of balls, 28 28 .
  • Step 2: Note the fraction representing the orange balls, 14 \frac{1}{4} .
  • Step 3: Apply the formula to find the number of orange balls:
    Number of orange balls =28×14 = 28 \times \frac{1}{4}

Now, let's perform the calculation:
28×14=28÷4=7 28 \times \frac{1}{4} = 28 \div 4 = 7

Therefore, the number of orange balls in the box is 7 7 .

Answer:

7

Video Solution
Exercise #3

There are two circles.

One circle has a radius of 4 cm, while the other circle has a radius of 10 cm.

How many times greater is the area of the second circle than the area of the first circle?

Step-by-Step Solution

The area of a circle is calculated using the following formula:

where r represents the radius.

Using the formula, we calculate the areas of the circles:

Circle 1:

π*4² =

π16

Circle 2:

π*10² =

π100

To calculate how much larger one circle is than the other (in other words - what is the ratio between them)

All we need to do is divide one area by the other.

100/16 =

6.25

Therefore the answer is 6 and a quarter!

Answer:

614 6\frac{1}{4}

Video Solution
Exercise #4

The rectangle ABCD is shown below.

AB = X

The ratio between AB and BC is x2 \sqrt{\frac{x}{2}} .


The length of diagonal AC is labelled m.

XXXmmmAAABBBCCCDDD

Determine the value of m:

Step-by-Step Solution

We know that:

ABBC=x2 \frac{AB}{BC}=\sqrt{\frac{x}{2}}

We also know that AB equals X.

First, we will substitute the given data into the formula accordingly:

xBC=x2 \frac{x}{BC}=\frac{\sqrt{x}}{\sqrt{2}}

x2=BCx x\sqrt{2}=BC\sqrt{x}

x2x=BC \frac{x\sqrt{2}}{\sqrt{x}}=BC

x×x×2x=BC \frac{\sqrt{x}\times\sqrt{x}\times\sqrt{2}}{\sqrt{x}}=BC

x×2=BC \sqrt{x}\times\sqrt{2}=BC

Now let's look at triangle ABC and use the Pythagorean theorem:

AB2+BC2=AC2 AB^2+BC^2=AC^2

We substitute in our known values:

x2+(x×2)2=m2 x^2+(\sqrt{x}\times\sqrt{2})^2=m^2

x2+x×2=m2 x^2+x\times2=m^2

Finally, we will add 1 to both sides:

x2+2x+1=m2+1 x^2+2x+1=m^2+1

(x+1)2=m2+1 (x+1)^2=m^2+1

Answer:

m2+1=(x+1)2 m^2+1=(x+1)^2

Video Solution
Exercise #5

Given the rectangle ABCD

AB=X the ratio between AB and BC is equal tox2 \sqrt{\frac{x}{2}}

We mark the length of the diagonal A A with m m

Check the correct argument:

XXXmmmAAABBBCCCDDD

Step-by-Step Solution

Let's find side BC

Based on what we're given:

ABBC=xBC=x2 \frac{AB}{BC}=\frac{x}{BC}=\sqrt{\frac{x}{2}}

xBC=x2 \frac{x}{BC}=\frac{\sqrt{x}}{\sqrt{2}}

2x=xBC \sqrt{2}x=\sqrt{x}BC

Let's divide by square root x:

2×xx=BC \frac{\sqrt{2}\times x}{\sqrt{x}}=BC

2×x×xx=BC \frac{\sqrt{2}\times\sqrt{x}\times\sqrt{x}}{\sqrt{x}}=BC

Let's reduce the numerator and denominator by square root x:

2x=BC \sqrt{2}\sqrt{x}=BC

We'll use the Pythagorean theorem to calculate the area of triangle ABC:

AB2+BC2=AC2 AB^2+BC^2=AC^2

Let's substitute what we're given:

x2+(2x)2=m2 x^2+(\sqrt{2}\sqrt{x})^2=m^2

x2+2x=m2 x^2+2x=m^2

Answer:

x2+2x=m2 x^2+2x=m^2

Video Solution

Frequently Asked Questions

How do you solve ratio word problems step by step?

+
First, identify what quantities are being compared and write the ratio. Then determine if you need part-to-part or part-to-whole ratios. Finally, set up the proportion and solve using cross multiplication or equivalent fractions.

What's the difference between a ratio and a proportion?

+
A ratio compares two quantities (like 3:5), while a proportion states that two ratios are equal (like 3:5 = 6:10). Ratios show relationships, proportions show equivalent relationships.

How do you find equivalent ratios?

+
Multiply or divide both terms of the ratio by the same number. For example, 2:3 becomes 4:6 (multiply by 2) or becomes 6:9 (multiply by 3). The relationship stays the same.

When do you use direct vs inverse proportion?

+
Use direct proportion when both quantities increase or decrease together (like distance and time at constant speed). Use inverse proportion when one increases as the other decreases (like speed and time for fixed distance).

How do you solve scale problems on maps?

+
Identify the scale ratio (like 1:50,000), set up a proportion with known and unknown distances, then cross multiply to find the answer. Always use the same units throughout.

What are the most common mistakes in ratio problems?

+
Common errors include: mixing up the order of terms in ratios, using different units without converting, confusing part-to-part with part-to-whole ratios, and incorrectly setting up proportions for word problems.

How do you distribute money according to a ratio?

+
Add the parts of the ratio to find total parts, divide the total amount by total parts to find one part's value, then multiply each ratio term by the value of one part.

Can ratios be written as fractions and percentages?

+
Yes, ratios can be expressed as fractions (3:4 = 3/4), decimals (0.75), or percentages (75%). This flexibility helps solve different types of proportion problems and makes comparisons easier.

Practice by Question Type

More Resources and Links