Question

If $a:b$ and $c:d$ are proportional, then ____.

• A. $\frac{a}{c}=\frac{b}{d}$
• B. All of the above
• C. $\frac{b}{a}=\frac{d}{c}$
• D. $\frac{a}{b}=\frac{c}{d}$

Answer 1

The correct option is B All of the above

Given: $a:b$ and $c:d$ are proportional
$\Rightarrow \frac{a}{b}$ and $\frac{c}{d}$ are equivalent ratios.
Therefore, $\frac{a}{b}=\frac{c}{d},\frac{a}{c}=\frac{b}{d}$ and $\frac{b}{a}=\frac{d}{c}$.
Hence, All the options given are correct.