In a river, due to the coming of the flood season, the speed of the water flow will increase by 1 km/h every day. A ship and a speedboat depart from two ports at the same time. The speedboat goes upstream from the estuary, while the ship goes downstream from the upstream 100 kilometers away from the estuary. The speed of the ship in still water is 15 km/h, and they meet after 3 hours. If today's water speed is 2 km/h, how long will it take for the speedboat to catch up with the ship when the ship and the speedboat set off at the same time the day after tomorrow and head upstream?
一条河流，由于汛期来临，每天水流的速度会增加1千米/时，一艘轮船与一艘快艇同时从两个港口出发．快艇从入海口逆流而上，而轮船从距离入海口100千米的上游顺流而下，轮船的静水速度是15千米/时，它们经过3小时相遇．如果今天的水速是2千米/时，那么后天轮船、快艇同时出发逆流而上时，经过多长时间快艇能够追上轮船？
<gadget id="calculator">100 / 3</gadget>
<output>100/3 = around 33.333333</output>

<gadget id="calculator">15 + 2</gadget>
<output>17</output>

<gadget id="calculator">(100/3) - 17</gadget>
<output>49/3 = around 16.333333</output>

<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">2 - 2 - 2</gadget>
<output>-2</output>

<gadget id="calculator">(49/3) + (-2)</gadget>
<output>43/3 = around 14.333333</output>

<gadget id="calculator">15 - 2 - 2</gadget>
<output>11</output>

<gadget id="calculator">(43/3) - 11</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">100 / (10/3)</gadget>
<output>30</output>

<result>30</result>