Gọi số công nhân đội A là x ; đội B là y ; đội C là z
\(\Rightarrow x-\dfrac{1}{3}x=y-\dfrac{1}{4}y=z-\dfrac{1}{5}z\)
\(\Rightarrow\dfrac{2}{3}x=\dfrac{3}{4}y=\dfrac{4}{5}z\)
\(\Rightarrow\dfrac{x}{\dfrac{3}{2}}=\dfrac{y}{\dfrac{4}{3}}=\dfrac{z}{\dfrac{5}{4}}=\dfrac{x+y+z}{\dfrac{3}{2}+\dfrac{4}{3}+\dfrac{5}{4}}=\dfrac{147}{\dfrac{49}{12}}=36\)
\(\Rightarrow\left\{{}\begin{matrix}x=36.\dfrac{3}{2}=54\\y=36.\dfrac{4}{3}=48\\z=36.\dfrac{5}{4}=45\end{matrix}\right.\)