Lenny is 36 years old and Max is 12 years old.
Step-by-step explanation
Suppose, the age of Max is
years.
As Lenny is 3 times older than Max, so the age of Lenny will be:
years.
Now, when you subtract Max's age from Lenny's age you get 24. So, the equation will be.....

So, the age of Max is 12 years and the age of Lenny is (3×12)= 36 years.