<meta charset="UTF-8">
<h3>¿Alcohol o gasolina?</h3>
<script>
    var tanque = 40
    var gasolina = 480
    var alcohol = 300
    document.write("Usando gasolina el total es de: " + (gasolina/tanque) + " Km/h." + "<br>");
    document.write("Usando alcohol el total es de: " + (alcohol/tanque) + " Km/h." + "<br>");
</script> 
            