If 1/3 + 1/2 + 1/x = 4, then x = ?

Answer: Option B

$$\begin{array}{rl}& \frac{1}{x}=4-\left(\frac{1}{3}+\frac{1}{2}\right)\\ & =4-\frac{2+3}{6}\\ & =4-\frac{5}{6}\\ & =\frac{24-5}{6}\\ & =\frac{19}{6}\\ & \Rightarrow x=\frac{6}{19}\end{array}$$