have two one-quart jars; the first is filled with water, and the second is empty. I pour half of the water in the first jar into the second, then a third of the water in the second jar into the first, then a fourth of the water in the first jar into the second, then a fifth of the water in the second jar into the first, and so on. How much water in quarts is in the first jar after the $10^{\textrm{th}}$ pour? Express your answer as a common fraction.