Lenny is 36 years old and Max is 12 years old.
Explanation
Suppose, the age of Max is [tex]x[/tex] years.
As Lenny is 3 times older than Max, so the age of Lenny will be: [tex]3x[/tex] years.
Now, when you subtract Max's age from Lenny's age you get 24. So, the equation will be.....
[tex]3x-x=24\\ \\ 2x=24\\ \\ x=\frac{24}{2}=12[/tex]
So, the age of Max is 12 years and the age of Lenny is (3×12)= 36 years.