Cars A and B travel towards each other from cities A and B at the same time and meet each other in 4 hours. The speed of car A is 15 kilometers faster than that of car B. It is known that the speed ratio of the two cars is 5:4. What is the distance in miles between A and B?
甲乙两车同时从A、B两城相向而行，4小时相遇．甲车的速度比乙车快15千米，已知两车的速度之比为5：4．A、B两城相距多少千米．
<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(5/4) - 1</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">15 / (1/4)</gadget>
<output>60</output>

<gadget id="calculator">60 * (5/4)</gadget>
<output>75</output>

<gadget id="calculator">60 + 75</gadget>
<output>135</output>

<gadget id="calculator">135 * 4</gadget>
<output>540</output>

<result>540</result>