For a you would have to multiply 0.11 by the amount of mi she drove which was 135mi that would give you $14.85 and then you would add the $27 since she rode the car for one day only and that would give you $41.85
And for b to start you would have to subtract $27 since he only rode for one day that would give you $44 then you would have to figure out how many mile he drove so you would divide 44 by 11 and that you give you 400 so he drove 400mi
Hope this helped
