How to set the default value for radio buttons in AngularJS?

I need to make a system to change the total price by number of tickets selected. I created some radio buttons to choose the number of ticket. The ploblem is that the default value is unset and the result is null on loading.

<code>
<input type="radio" ng-model="people" value="1" checked="checked"><label>1</label>
<input type="radio" ng-model="people" value="2"><label>2</label>
<input type="radio" ng-model="people" value="3"><label>3</label>
<ul>
  <li>{{10*people}}€</li>
  <li>{{8*people}}€</li>
  <li>{{30*people}}€</li>
</ul>
</code>

Please see my jsfiddle.

Set a default value for people with ngInit

<div ng-app>
    <div ng-init="people=1" />
        <input type="radio" ng-model="people" value="1"><label>1</label>
        <input type="radio" ng-model="people" value="2"><label>2</label>
        <input type="radio" ng-model="people" value="3"><label>3</label>
    <ul>
        <li>{{10*people}}€</li>
        <li>{{8*people}}€</li>
        <li>{{30*people}}€</li>
    </ul>
</div>

Demo: Fiddle

<div ng-app="" ng-controller="myCntrl">    
        <input type="radio" ng-model="people" value="1"/><label>1</label>
        <input type="radio" ng-model="people" value="2"/><label>2</label>
        <input type="radio" ng-model="people" value="3"/><label>3</label>
</div>
<script>
    function myCntrl($scope){
        $scope.people=1;
    }
</script>