Bunuel
There are five members in a family — a couple and their three children. What is the age of the father?
(1) The age of the father is three times the sum of the ages of the two elder children and 11 years more than the sum of the squares of the ages of two younger children.
(2) The average age of the family is 21 years and the mother’s age is greater than 40 years and less than father’s age.
family ; f+m+x1+x2+x3
#1
The age of the father is three times the sum of the ages of the two elder children and 11 years more than the sum of the squares of the ages of two younger children.
f=3(x1+x2)+(11+x2^2+x3^2)
insufficient
#2
The average age of the family is 21 years and the mother’s age is greater than 40 years and less than father’s age.
f+m+x1+x2+x3=105
m>40<f
we can get many values for f & m insufficient
from 1 &2
we get
4x1+x2(4+x2)+x3^2+m=94
relation b/w m and children is not clear ; insufficient
IMO E