Question 194737
In order for the years of their birth to be divisible by 4 Joss had to be born in a year ending with 9 
19x9 is Joss' birth date. since 1+9+9=19 the x must be 1 or 5.
1920 is divisible by 4. So is 1960 but their ages wouldn't be over 100.
1919 Answer.
.
Ed