Question 927401
1     2      3      5      7     11     13     17     19     23     29 31     37     41     43     47  
f + x + y + z = 50
x + y + z + 3n = 2(f+n)
........
f + x + y + z = 50  
f = 29
x + y + z = 21,  Childen: 1, 7, 13
21 + 3n = 2(29+n)
n = 58 - 21 = 37 years
And...in 37 years...
38 + 44 + 50 = 2(29+37) = 132  checks