College

Which of the following proportions is false?

A. [tex]\frac{18}{48}=\frac{20}{50}[/tex]
B. [tex]\frac{10}{25}=\frac{40}{100}[/tex]
C. [tex]\frac{24}{30}=\frac{20}{25}[/tex]
D. [tex]\frac{25}{45}=\frac{75}{135}[/tex]

Answer :

To find which proportion is false, we'll examine the given fractions one by one to see if they are equal:

1. Proportion 1: [tex]\(\frac{18}{48} = \frac{20}{50}\)[/tex]

To check if these fractions are equal, we can cross-multiply and compare the products:
- Multiply 18 by 50: [tex]\(18 \times 50 = 900\)[/tex]
- Multiply 48 by 20: [tex]\(48 \times 20 = 960\)[/tex]

Since [tex]\(900 \neq 960\)[/tex], this proportion is false.

2. Proportion 2: [tex]\(\frac{10}{25} = \frac{40}{100}\)[/tex]

Check if these fractions are equal by cross-multiplying:
- Multiply 10 by 100: [tex]\(10 \times 100 = 1000\)[/tex]
- Multiply 25 by 40: [tex]\(25 \times 40 = 1000\)[/tex]

Since [tex]\(1000 = 1000\)[/tex], this proportion is true.

3. Proportion 3: [tex]\(\frac{24}{30} = \frac{20}{25}\)[/tex]

Check if these fractions are equal by cross-multiplying:
- Multiply 24 by 25: [tex]\(24 \times 25 = 600\)[/tex]
- Multiply 30 by 20: [tex]\(30 \times 20 = 600\)[/tex]

Since [tex]\(600 = 600\)[/tex], this proportion is true.

4. Proportion 4: [tex]\(\frac{25}{45} = \frac{75}{135}\)[/tex]

Check if these fractions are equal by cross-multiplying:
- Multiply 25 by 135: [tex]\(25 \times 135 = 3375\)[/tex]
- Multiply 45 by 75: [tex]\(45 \times 75 = 3375\)[/tex]

Since [tex]\(3375 = 3375\)[/tex], this proportion is true.

From these steps, we found that the first proportion, [tex]\(\frac{18}{48} = \frac{20}{50}\)[/tex], is false.