# Mark bought 16 packages of water balloons for his birthday party. Altogether, he bought 512 water balloons. How many balloons were in each package?

$32$
If Mark bought 16 packages, and there were 512 balloons in total, you can set up the equation 512-:16=?. This is because the 512 ballons were distributed evenly among the packages, and you just need to find out how many are in each one. Solve this problem, and you get $32$ balloons per package.