Question 9 of 25

The ratio of the surface areas of two similar solids is [tex]$49: 100$[/tex]. What is the ratio of their corresponding side lengths?

A. [tex]$\frac{49}{10}: 10$[/tex]
B. [tex]$7: \frac{100}{7}$[/tex]
C. [tex]$7: 10$[/tex]
D. [tex]$1: 24$[/tex]



Answer :

To determine the ratio of the corresponding side lengths of two similar solids when the ratio of their surface areas is given, we need to follow these steps:

1. Understanding the Given Ratio:
The ratio of the surface areas of the two similar solids is given as [tex]\(49:100\)[/tex]. This can be written as a fraction:
[tex]\[ \text{Surface area ratio} = \frac{49}{100} \][/tex]

2. Relating Surface Area and Side Lengths:
For similar solids, the ratio of their surface areas is the square of the ratio of their corresponding side lengths. Let's denote the ratio of the side lengths as [tex]\(\frac{a}{b}\)[/tex]. Therefore, we have:
[tex]\[ \left(\frac{a}{b}\right)^2 = \frac{49}{100} \][/tex]

3. Finding the Ratio of Side Lengths:
To find the actual ratio of side lengths ([tex]\(\frac{a}{b}\)[/tex]), we need to take the square root of both sides of the surface area ratio equation:
[tex]\[ \frac{a}{b} = \sqrt{\frac{49}{100}} \][/tex]

Calculate the square root of the numerator and the denominator separately:
[tex]\[ \sqrt{49} = 7 \quad \text{and} \quad \sqrt{100} = 10 \][/tex]

So, the ratio of the side lengths is:
[tex]\[ \frac{a}{b} = \frac{7}{10} \][/tex]

4. Simplifying the Ratio:
The ratio [tex]\(\frac{7}{10}\)[/tex] is already in its simplest form. Therefore, the ratio of the corresponding side lengths of the two similar solids is [tex]\(7:10\)[/tex].

Thus, the correct answer is:
C. [tex]\(7: 10\)[/tex]