Julia’s boat sprang a leak while she was out on the lake. The boat was taking on two liters of water for every ten feet she rowed back towards shore. It took her sixteen seconds to row twenty feet. The shore was 64 seconds away. How much water had the boat taken on by the time Julia reached shore?
It took Julia 64 seconds to reach shore, so it took 64 / 16 = 
<gadget id="calculator">64/16</gadget>
<output>4</output>
4 times rowing 20 feet to reach the shore.
Thus, she had to row 20 * 4 = 
<gadget id="calculator">20*4</gadget>
<output>80</output>
80 feet back to shore.
In those 80 feet, she took on 2 liters of water 80 / 10 = 
<gadget id="calculator">80/10</gadget>
<output>8</output>
8 times.
Thus, the boat had taken on 8 * 2 = 
<gadget id="calculator">8*2</gadget>
<output>16</output>
16 liters of water by the time Julia reached the shore.

<result>16</result>