High School

Below are pairs of ratios. Select all pairs that represent equivalent ratios.

A. [tex]$5: 6$[/tex] and [tex]$6: 7$[/tex]

B. [tex]$36: 35$[/tex] and [tex]$4: 3$[/tex]

C. [tex]$2: 3$[/tex] and [tex]$12: 18$[/tex]

D. [tex]$4: 8$[/tex] and [tex]$20000: 40000$[/tex]

E. [tex]$45: 18$[/tex] and [tex]$5: 2$[/tex]

Answer :

Sure! Let's find the equivalent ratios step-by-step.

A ratio of [tex]\(a:b\)[/tex] is equivalent to another ratio [tex]\(c:d\)[/tex] if [tex]\(\frac{a}{b} = \frac{c}{d}\)[/tex]. This can also be checked using cross-multiplication: [tex]\(a \times d = b \times c\)[/tex].

Let's examine each pair:

1. Ratios [tex]\(5:6\)[/tex] and [tex]\(6:7\)[/tex]:
- Cross-multiplying gives: [tex]\(5 \times 7 = 35\)[/tex] and [tex]\(6 \times 6 = 36\)[/tex]
- Since [tex]\(35 \neq 36\)[/tex], these ratios are not equivalent.

2. Ratios [tex]\(36:35\)[/tex] and [tex]\(4:3\)[/tex]:
- Cross-multiplying gives: [tex]\(36 \times 3 = 108\)[/tex] and [tex]\(35 \times 4 = 140\)[/tex]
- Since [tex]\(108 \neq 140\)[/tex], these ratios are not equivalent.

3. Ratios [tex]\(2:3\)[/tex] and [tex]\(12:18\)[/tex]:
- Cross-multiplying gives: [tex]\(2 \times 18 = 36\)[/tex] and [tex]\(3 \times 12 = 36\)[/tex]
- Since [tex]\(36 = 36\)[/tex], these ratios are equivalent.

4. Ratios [tex]\(4:8\)[/tex] and [tex]\(20000:40000\)[/tex]:
- Cross-multiplying gives: [tex]\(4 \times 40000 = 160000\)[/tex] and [tex]\(8 \times 20000 = 160000\)[/tex]
- Since [tex]\(160000 = 160000\)[/tex], these ratios are equivalent.

5. Ratios [tex]\(45:18\)[/tex] and [tex]\(5:2\)[/tex]:
- Cross-multiplying gives: [tex]\(45 \times 2 = 90\)[/tex] and [tex]\(18 \times 5 = 90\)[/tex]
- Since [tex]\(90 = 90\)[/tex], these ratios are equivalent.

Therefore, the pairs that represent equivalent ratios are:

- [tex]\(2:3\)[/tex] and [tex]\(12:18\)[/tex]
- [tex]\(4:8\)[/tex] and [tex]\(20000:40000\)[/tex]
- [tex]\(45:18\)[/tex] and [tex]\(5:2\)[/tex]

So, the selected pairs are:

- [tex]\(3^\text{rd}~ pair\)[/tex]
- [tex]\(4^\text{th}~ pair\)[/tex]
- [tex]\(5^\text{th}~ pair\)[/tex]

These are the equivalent ratios.