If $m+1=\frac{n-2}{3}$, what is the value of $3 m-n$ ?
(A) -1
(B) -5
(C) -3
(D) -9
(E) -7
Since $m+1=\frac{n-2}{3}$, then $3(m+1)=n-2$.

This means that $3 m+3=n-2$ and so $3 m-n=-2-3=-5$.

ANSWER: (B)