Answer:
6.5 km
Explanation:
First subtract 1.2 from 12, you get 10.8
now you are going to divide 10.8 by .90, you get 12. Now this may seem confusing but now u have do divided it by .5 because you aren't paying for every 1 km you are paying fro every .5 km. So now u have 6 km but no add that extra .5 from earlier and you get 6.5 km.
12.00-1.2=10.8 this is .5 km 10.8 divided by .9 =12
12 divided by .5=6
.5 km + 6 km = 6.5