your work looks good, the ages will be
[tex]\bf \stackrel{\textit{20 to 30}}{25\%}~~+~~\stackrel{\textit{31 to 40}}{22\%}~~+~~\stackrel{\textit{41 to 50}}{13\%}\implies 60\%
\\\\\\
\textit{60\% of 125000}\implies \cfrac{60}{100}\cdot 125000\implies 75000[/tex]
