(1-11/36x3)+(3-11/36x5)+(5-11/36x7)+(7-11/36x9)+(9-11/36x11)+(11-11/36x13)=1+3+5+7+9+11-(33/36+55/36+77/36+99/36+121/36+143/36)=36-(33/36+55/36+77/36+99/36+121/36+143/36)=36-44/3=64/3
