Question 1143511
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The volume of the tank is  6*12*18 = 1296 cubic meters.


It was 2/3 full water -- hence, the water volume was  {{{(2/3)*1296}}} = 864 cubic meters originally.


After adding 120 cubic meters of water, the water volume in the tank is

    864 + 120 = 984 cubic meters.


The percentage is  {{{(984/1296)*100}}} = 75.93%.      <U>ANSWER</U>
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