At the start of an e x periment on the rate of evaporation, some water was left in a cylinder.<br>After two days, the amount of water decreased by 25% to 90 $$ml$$.<br>After another two days, the amount of water decreased further by 30%. <hr> How much water was there in the cylinder after four days? <br> <input min="0" type="number" id ="imp6pg106q7a_1" class="lineinput" placeholder="?" />