div
{
  padding:20px;
  margin: 5px;
  float: left;
}

#parent-div
{
  width:500px;
  background: gray;
}
#box-one
{
  background: skyblue;
    width:70px;
}
#box-two
{
  background: green;
    width: 70px;
}
#box-three
{ 
  background: brown;
  width:70px;
}