Typists

Using joint variation $k=\frac{x\cdot y}{z}$ where k is a constant, the product $x\cdot y$ is the "manhours" or total time spent on a project, and z is the pages produced.

$k=\frac{x\cdot y}{z} \Rightarrow k=\frac{2\cdot 2}{2}=2$

Thus

$2=\frac{x\cdot 6}{18} \Rightarrow \frac{2\cdot 18}{6} = x \Rightarrow x=6$

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