.container{
  margin:0 -1.6666%;
  width:300px;
  padding:10px 0;
  overflow:hidden;
}
.container .item{
  width:30%;
  margin:0 1.6666%;

  float:left;
  text-align:center;
  background-image:url(http://www-creators.com/wp-content/uploads/2017/05/1.png);
  background-size:cover;
  background-repeat:no-repeat;
  background-position:center;
}
.container .item:before{
  content:'';
  display:block;
  width:100%;
  height:0;
  padding-bottom:50%;
}