Aweek before election 1,500 people were asked who they planed to vote for, 45% said they planned to vote for candidate x. 38% said they planned to vote for candidate y. the rest said they weren't sure .how many of the people who were asked have not yet decided for whom they plan to vote?

By difference, the percentage of people who are not sure who to vote is 100% - 45% - 38% = 17%. The number of people who have not yet decided to whom their votes goes is the product of 1,500 and 17% in its decimal equivalent.
                                (1,500) x (0.17) = 255
Therefore, 255 have not yet decided who to vote. 

The answer would be the second choice : )