At first, Kenny and Patrick had the same amount of water in each of their water bottles. After Kenny drank thrice as much water as Patrick, Kenny had 50 ml of water left while Patrick had 350 $$ml$$ of water left. <hr> Each of them had <input min="0" type="number" id ="imp5pg022q14_1" class="lineinput" placeholder="?" /> $$ml$$ of water at first.