They would have used a total of 30 horses. Each person would've each ridden 15 so 15+15= 30 and 165 divided by 11 is 15. Hope this is off help!
A' (3(-5),3(-4))= (-15,-12)
B' (3(2),3(6))=(6,18)
C'(3(4),3(-3))=(12,-9)
