Answer:
john 2 1/2 years old jack is 7
in 5 years he will be 7 like jack is now
in two years jack is 9 and john is 4.5
Explanation:
You could also say john is 3 and jack 8 in 5 years he is 8 like jack
and in 2 years he is 5 and jack is 10 which is twice the age.
it doesn't work for other ages.