Question

Which of the ratios form a proportion $?$

• A. $5$ to $2$and $4$to $10$
• B. $2:3$ to $7:8$
• C. $3$ to $2$ and $15$ to $10$
• D. $12:8$ and $8:42$

Answer 1

The correct option is C

$3$ to $2$ and $15$ to $10$

Checking the ratios which forms a proportion:

A. $\frac{4}{10}=\frac{5}{2}$ (dividing both sides by $2$) $\ne \frac{5}{2}$so this ratio doesn’t form a proportion.

B. $\frac{2}{3}\ne \frac{7}{8}$so this ratio doesn’t form a proportion.

C. $\frac{15}{10}=\frac{3}{2}$ (dividing both sides by $5$) so this ratios form a proportion

D. $12:8$ and $8:42$

$\Rightarrow$Divide by $2$ on both sides
$\Rightarrow$$6:4$ and $4:21$

$\Rightarrow$Again, divide by $2$ on both sides

$\Rightarrow$$3.2$ and $2:21.5$ so, this ratio also doesn’t form any proportion

A comparison by division is termed as ratio and the equality of two ratios is called proportion.

Therefore, $3$ to $2$ and $15$ to $10$ is the ratios form a proportion.

Hence, $3$ to $2$ and $15$ to $10$ is the ratios form a proportion.