Question 981989
.
John + Jerry=42 years
John = Jerry + 2 yrs (John is always 2 years older than Jerry)
Jerry + 2yrs + Jerry=42 years
2 Jerry=40 yrs 
Jerry=20 years old.
John=Jerry + 2yrs=20yrs + 2yrs=22years old.
ANSWER: John is 22 years old and Jerry is 20 years old.