A rope is folded into 4 strands and 5 strands. The length of 4 strands is 0.75 meters longer than that of 5 strands. How many meters is this rope?
一根绳子折成4股和5股，折成4股比折成5股的长0.75米，这根绳子长多少米？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">0.75 / (1/20)</gadget>
<output>15</output>

<result>15</result>