Cut a rope into two according to the ratio of 5:3, the longer one is 2.5 meters longer than the shorter one, what is the original length of the rope?
把一根绳子按5：3截成两段，长的一段比短的长2.5米，这根绳子原来长是多少米？
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">2.5 / 2</gadget>
<output>1.25</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">1.25 * 8</gadget>
<output>10</output>

<result>10</result>