Aligning divs horizontally inside a div that hides overflow

[Dromych]

Say I have this HTML: \[code\]<style>.b{float:left; width: 300px; height: 300px;}</style><div style="overflow:hidden;width:300px;height:300px;" id="a"> <div class="b" style="background-color: red"></div> <div class="b" style="background-color: green"></div> <div class="b" style="background-color: blue"></div></div>\[/code\]I want the \[code\].b\[/code\] divs to sit on one line. However, they only do this when \[code\]#a\[/code\]'s overflow is normal.