fiona finds 1 shell on her first day.every day that week she finds twice as many shells. how many does fiona find on the seventh day.
14 shells
128 shells
1+2+3+6+12+24+48=96 shells
or
1+2+2+2+2+2+2=13 shells
You guys are all wrong, it's 64
1 + 2 + 4 + 8 + 16 + 32 + 64, oops, I was wrong, it was 127
wait, do you mean 2wice as many shells as the previous day, or 2wice as many as she already had?
+165 
