Percentage of voters who voted = \(60\%\)Percentage of those who did not vote = \(100\% - 60\% = 40\%\)Number of people who did not vote = \(40\% \;of\; 15000\)
= \(\frac{40}{100}\times 15000\)
= \(6000\)
Therefore, \(6000\) people did not vote.