A wizard prepares a magic potion by mixing two key ingredients.<br>For every 10 $$ml$$ of snake's blood, he needs 25 $$ml$$ of bat's saliva. <hr> If he has 40 $$ml$$ of snake's blood, how much bat's saliva does he need? <br> <input min="0" type="number" id ="imp6pg083q5b_1" class="lineinput" placeholder="?" />