Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.7)
// Compass (v1.0.0.alpha.18)
// ----

//assignment 1
.car {
  zoom: 1;
  &__tire {
    zoom: 2;
  }
  &--bmw {
    zoom: 3;
    &__tire {
      zoom: 4;
    }
  }
}

//assignment 2
p {
  box-shadow: 0 0 5px #000;
  
   .no-boxshadow & {
     border: solid 1px #000;
   }
}

//assignment 3
@mixin box-sizing($box-model) {
  -webkit-box-sizing: $box-model;
  -moz-box-sizing: $box-model;
  box-sizing: $box-model;
}

@mixin rotate($degrees) {
  -ms-transform: rotate(#{$degrees}deg);
  transform: rotate(#{$degrees}deg);
}

p {
  @include box-sizing(border-box);
  @include rotate(90);
}

SassMeister-output.css

.car {
  zoom: 1;
}
.car__tire {
  zoom: 2;
}
.car--bmw {
  zoom: 3;
}
.car--bmw__tire {
  zoom: 4;
}

p {
  box-shadow: 0 0 5px #000;
}
.no-boxshadow p {
  border: solid 1px #000;
}

p {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  -ms-transform: rotate(90deg);
  transform: rotate(90deg);
}