Question

If $a$ and $b$ are two positive real numbers, then $a>b$ implies _______

• A. $-a>-b$
• B. $-\frac{1}{a}>\frac{1}{b}$
• C. $-a<-b$
• D. $a\le b$

Answer 1

The correct option is C $-a<-b$

We know that multiplication with minus sign changes the sign of inequality.

This can be understand by taking examples.

Let $a=5$ and $b=3$, then $a>b$

But $-a=-5$ and $-b=-3$ this implies that $-5<-3$

So $-a<-b$

Hence, the correct answer will be option C.