Question 421459
Carl's age now = c
Patricia's age now = 30 - c 
==> 3(c - 13) = (30 - c) - 13
==> 3c - 39 = 17 - c
==> 4c = 56
==> c = 14, Carl's age now, and 
30 - c = 30 - 14 = 16, Patricia's age now.