<script>
  function test()
  {
    var radio4 = document.getElementById("radio4").checked;
    var radio6 = document.getElementById("radio6").checked;
    var radio12 = document.getElementById("radio12").checked;
    var result = document.getElementById("result");
    var r=0;
    if (radio4) r++;
    if (radio6) r++;
    if (radio12) r++;
    result.innerHTML = r;

  }
</script>
<form>
    <h3>Pytanie 1: Co oznacza po ang. cat?</h3>
    <input type="radio" name="radio1" id="radio1"> pies<br>
    <input type="radio" name="radio1" id="radio2"> ryś<br>
    <input type="radio" name="radio1" id="radio3"> łoś<br>
    <input type="radio" name="radio1" id="radio4"> kot<br>
    <br>
    <h3>Pytanie 2: Co oznacza po ang. red?</h3>
    <input type="radio" name="radio2" id="radio5"> biały<br>
    <input type="radio" name="radio2" id="radio6"> czerwoy<br>
    <input type="radio" name="radio2" id="radio7"> biebieski<br>
    <input type="radio" name="radio2" id="radio8"> czarny<br>
    <br>
    <h3>Pytanie 3: Co oznacza po ang. bird?</h3>
    <input type="radio" name="radio3" id="radio9"> pies<br>
    <input type="radio" name="radio3" id="radio10"> ryś<br>
    <input type="radio" name="radio3" id="radio11"> ryba<br>
    <input type="radio" name="radio3" id="radio12"> ptak<br>
    <br>
    <input type="button" value="Sprawdź" onclick="test()"><br>
</form>
Wynik: <span id="result">0</span>