Question

If numbers $\frac{a}{b}$ and $\frac{c}{d}$ two rational numbers such that b, d are positive and if $\frac{a}{b}$ > $\frac{c}{d}$, then :

• A. $ad\ge bc$
• B. ad = bc
• C. ad > bc
• D. ad < bc

Answer 1

The correct option is C ad > bc

Comparison of two rational numbers $\frac{a}{b}$, $\frac{c}{d}$ can be done using following rules :
i) If $\frac{a}{b}$ > $\frac{c}{d}$, then ad > bc.
ii) If $\frac{a}{b}$ < $\frac{c}{d}$, then ad < bc.
iii) If $\frac{a}{b}$ = $\frac{c}{d}$, then ad = bc.

So, as it is given $\frac{a}{b}$ > $\frac{c}{d}$, the answer is ad > bc.