If 17/27 represents the "voted in favour" group, then 10/27 represents the opposition "voted against". Therefore, 10/27 is 350 people, since 17/27+10/27=1 or 100% of the people. To find how many people voted we divide 350 by 10/27, which is the same as multiplying by 27/10=35*27=945. (17/27 is "voted current" group=595. 595+350=945.)