At first, Nathan and Jack had the same amount water in each of their water bottles.<br>Then, Nathan drank 150 $$ml$$ of water from his water bottle and Jack drank 80 $$ml$$ of water from his water bottle.<br>After that, Jack's water bottle contained thrice as much water as Nathan's water bottle.<hr>Each of them had <input min="0" type="number" id ="imp5pg013q11_1" class="lineinput" placeholder="?" /> $$ml$$ of water at first.