Answer:
997
Explanation:
Well let's find the square root of 2011 because Paul and his wife are about the same age.
![√(2011)](https://img.qammunity.org/2021/formulas/mathematics/high-school/usu2int8jra2rugront6wpp9enbh7msy90.png)
= 44.8
Paul is 45 and his wife is 44.
44 + 45 = 1980.
2011 - 1980
= 31
So the children are 15 and 16.
45 + 44 + 15 + 16
= 997
Paul and wife - 45 and 44
Children - 15 and 16
Thus,
13 years ago they would be 997.
Hope this helps :)