Suppose B gets X, then A gets 9/ 17x. According to the meaning of the question:
X+9/ 17x=208
X= 136 (min)
So B got 136, and A got 72.
Suppose the armor has X rounds and (10-x) rounds miss the target.
20x- 12( 10-x)=72
X=6 (hair)
Suppose B hits X rounds, then (10-x) rounds miss the target.
20x- 12( 10-x)= 136
X=8 (hair)
A: A took six shots and B took eight.