X 12 : 8000 x (12 - 3) : 20000 x 2
= 4 x 12 : 8 x 9 : 20 x 2
= 6 : 9 : 5
Let,
A's share = 6N
B's share = 9N
C's share = 5N
According to the question,
6N + 9N + 5N = 16800
20N = 16800
N = 16800/20 = 840
A's share = 6N = 6 x 840 = 5040
B's share = 9N = 9 x 840 = 7560
C's share = 5N = 5 x 840 = 4200