Flexibility, growth and contraction ratio

How much of the remaining free space (in pixels) will the third item get considering the defined properties?

<div class="flex-container">
  <div class="item1">Some text</div>
  <div class="item2">Some text</div>
  <div class="item3">Some text</div>
</div>

.flex-container{
  display: flex;
  width: 500px;
}

.item1{
  flex-basis: 100px; 
  flex-grow: 1;
}

.item2{
  flex-basis: 100px; 
  flex-grow: 1;
}

.item3{
  flex-basis: 100px; 
  flex-grow: 2;
}