Question

I need help with this question.

Answer 1

We can see that $a$ lies just before 0, $b$ lies between 2 and 3m and $c$ lies between 4 and 5. So, we have

$-1 < a < 0,\quad 2 < b < 3,\quad 4 < c < 5$

In particular, this implies that

$-1+4 < a+c < 0+5 \iff 3 < a+c < 5$

So, the correct order would be

$-2,\ b,\ a+c$