A boat sails from A to B, sails against the current, travels 24 kilometers per hour, and arrives at B. Returning from point B to point A again, arriving 2.5 hours earlier than sailing against the current. Given that the velocity of the water is 3 kilometers per hour, what is the distance in kilometers between A and B?
一只船从甲地开往乙地，逆水航行，每小时行24千米，到达乙地后．又从乙地返回甲地，比逆水航行提前2.5小时到达．已知水流速度是每小时3千米，甲、乙两地间的距离是多少千米？
<gadget id="calculator">2.5 * 24</gadget>
<output>60</output>

<gadget id="calculator">2.5 * 3</gadget>
<output>7.5</output>

<gadget id="calculator">60 + 7.5 + 7.5</gadget>
<output>75</output>

<gadget id="calculator">1 / 24</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">(1/24) * 24</gadget>
<output>1</output>

<gadget id="calculator">(1/24) * 3</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/8) - 1</gadget>
<output>-7/8 = around -0.875</output>

<gadget id="calculator">1 + (1/8) + (-7/8)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">75 / (1/4)</gadget>
<output>300</output>

<result>300</result>