*{
    box-sizing: border-box;
}

#padre{
    width: 100%;
    height: 300px;
    padding: 1%;
    background-color: rgb(65, 193, 207);
    display: flex;
    justify-content: space-between;
}
#hijo1{
    width: 20%;
    height: 266px;
   
    background-color: red;
}
#hijo2{
    width: 20%;
    height: 266px;
   
    margin-left: 1%;
    background-color: rgb(177, 200, 27);
}
#hijo3{
    width: 20%;
    height: 266px;
   
    margin-left: 1%;
    background-color: rgb(44, 159, 5);
}