<img id="img_1" src="주소" alt="설명" style="display: none" />
<img id="img_2" src="주소" alt="설명" style="display: none" />
<img id="img_3" src="주소" alt="설명" style="display: none" />
<img id="img_4" src="주소" alt="설명" style="display: none" />
<img id="img_5" src="주소" alt="설명" style="display: none" />
<script type="text/javascript">
var rand_num = Math.floor(Math.random() * 5) + 1;
document.getElementById('img_'+rand_num).style.display = 'block';
</script>
랜덤이미지 출력하기
