Beibei and Tiantian went from A to B at the same time. Beibei took 10 hours, which was 4 hours longer than Tiantian. It is known that the speed difference between the two is 5 kilometers. The distance between A and B is How many kilometers?
贝贝、甜甜二人同时从A地到B地，贝贝用了10小时，比甜甜多用了4小时，已知二人的速度差是5千米，A，B两地的距离是多少千米？
<gadget id="calculator">5 * 10</gadget>
<output>50</output>

<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">50 - 20</gadget>
<output>30</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) * 4</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/10) * 10</gadget>
<output>1</output>

<gadget id="calculator">(2/5) - 1</gadget>
<output>-3/5 = around -0.6</output>

<gadget id="calculator">1 + (-3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">30 / (2/5)</gadget>
<output>75</output>

<result>75</result>