Find all numbers for which the system of congruences
x = r (mod 6)
x = 13 (mod 20)
x = 38 (mod 45) has a solution.
r = 5
x mod 6 = 5 x mod 20 = 13 x mod 45 = 38
x = 180c + 173, where c=0, 1, 2,3..........etc.
