80% of (Cost) = $68
80% is also 0.8:
0.8 x Cost = $68
dividing each side by 0.8
Cost = 68 / 0.8 = 85 = $85
I believe that would be 7
I would would say 7.
Mom + Dad + daughter + daughter + daughter + daughter + plus one brother = 7
Since they are all sisters and it says each one has one brother I think that would mean 7. That's just my comprehension of the question, though I may 100% wrong.