Which of the following inequalities is correct?

A. [tex]\frac{2}{3}\ \textless \ \frac{3}{5}\ \textless \ \frac{5}{7}[/tex]

B. [tex]\frac{2}{3}\ \textless \ \frac{5}{7}\ \textless \ \frac{3}{5}[/tex]

C. [tex]\frac{3}{5}\ \textless \ \frac{2}{3}\ \textless \ \frac{5}{7}[/tex]

D. [tex]\frac{3}{5}\ \textless \ \frac{5}{7}\ \textless \ \frac{2}{3}[/tex]



Answer :

To determine which inequality is correct, we will evaluate each inequality step-by-step.

Inequality 1: [tex]\(\frac{2}{3} < \frac{3}{5} < \frac{5}{7}\)[/tex]

1. Compare [tex]\(\frac{2}{3}\)[/tex] and [tex]\(\frac{3}{5}\)[/tex]:
[tex]\[ \text{Cross-multiply:} \quad 2 \cdot 5 = 10 \quad \text{and} \quad 3 \cdot 3 = 9 \][/tex]
[tex]\[ \text{Since } 10 > 9, \quad \frac{2}{3} > \frac{3}{5} \][/tex]
This makes the inequality false.

Inequality 2: [tex]\(\frac{2}{3} < \frac{5}{7} < \frac{3}{5}\)[/tex]

1. Compare [tex]\(\frac{2}{3}\)[/tex] and [tex]\(\frac{5}{7}\)[/tex]:
[tex]\[ \text{Cross-multiply:} \quad 2 \cdot 7 = 14 \quad \text{and} \quad 3 \cdot 5 = 15 \][/tex]
[tex]\[ \text{Since } 14 < 15, \quad \frac{2}{3} < \frac{5}{7} \][/tex]

2. Compare [tex]\(\frac{5}{7}\)[/tex] and [tex]\(\frac{3}{5}\)[/tex]:
[tex]\[ \text{Cross-multiply:} \quad 5 \cdot 5 = 25 \quad \text{and} \quad 7 \cdot 3 = 21 \][/tex]
[tex]\[ \text{Since } 25 > 21, \quad \frac{5}{7} > \frac{3}{5} \][/tex]
This makes the inequality false.

Inequality 3: [tex]\(\frac{3}{5} < \frac{2}{3} < \frac{5}{7}\)[/tex]

1. Compare [tex]\(\frac{3}{5}\)[/tex] and [tex]\(\frac{2}{3}\)[/tex]:
[tex]\[ \text{Cross-multiply:} \quad 3 \cdot 3 = 9 \quad \text{and} \quad 5 \cdot 2 = 10 \][/tex]
[tex]\[ \text{Since } 9 < 10, \quad \frac{3}{5} < \frac{2}{3} \][/tex]

2. Compare [tex]\(\frac{2}{3}\)[/tex] and [tex]\(\frac{5}{7}\)[/tex]:
[tex]\[ \text{Cross-multiply:} \quad 2 \cdot 7 = 14 \quad \text{and} \quad 3 \cdot 5 = 15 \][/tex]
[tex]\[ \text{Since } 14 < 15, \quad \frac{2}{3} < \frac{5}{7} \][/tex]
This makes the inequality false.

Inequality 4: [tex]\(\frac{3}{5} < \frac{5}{7} < \frac{2}{3}\)[/tex]

1. Compare [tex]\(\frac{3}{5}\)[/tex] and [tex]\(\frac{5}{7}\)[/tex]:
[tex]\[ \text{Cross-multiply:} \quad 3 \cdot 7 = 21 \quad \text{and} \quad 5 \cdot 5 = 25 \][/tex]
[tex]\[ \text{Since } 21 < 25, \quad \frac{3}{5} < \frac{5}{7} \][/tex]

2. Compare [tex]\(\frac{5}{7}\)[/tex] and [tex]\(\frac{2}{3}\)[/tex]:
[tex]\[ \text{Cross-multiply:} \quad 5 \cdot 3 = 15 \quad \text{and} \quad 7 \cdot 2 = 14 \][/tex]
[tex]\[ \text{Since } 15 > 14, \quad \frac{5}{7} < \frac{2}{3} \][/tex]
This makes the inequality true.

So, the inequality that is correct is:

[tex]\[ \boxed{\frac{3}{5} < \frac{5}{7} < \frac{2}{3}} \][/tex]