Notăm cele trei numere cu a, b, c.
[tex]\it m_a=\dfrac{a+b+c}{3}=72 \Rightarrow a+b+c=216\ \ \ \ \ \ (1)\\ \\ \\ b > a\ cu\ \ 50\%\ din\ a \Rightarrow b=\ \ ^{100)}a+\dfrac{50}{100} a \Rightarrow b=\dfrac{150}{100}a \Rightarrow b=1,5a\ \ \ \ (2)\\ \\ \\ c > b\ cu\ \dfrac{b}{3} \Rightarrow c=b+\dfrac{b}{3}\ \stackrel{(2)}{\Longrightarrow}\ c=1,5a+\dfrac{1,5a}{3} \Rightarrow c=1,5a+0,5a=2a\ \ \ (3)\\ \\ \\ (1), (2), (3)\Rightarrow a+1,5a+2a=216 \Rightarrow 4,5a=216|_{\cdot2} \Rightarrow 9a=432|_{:9} \Rightarrow a=48\\ \\ b=1,5\cdot48=;\ \ c=2\cdot48[/tex]
