A rope is folded in half three times and measured to be 15 cm. How many centimeters was this rope originally?
一根绳子对折3次后量得是15厘米．这根绳子原来长多少厘米？
<gadget id="calculator">2 * 2 * 2</gadget>
<output>8</output>

<gadget id="calculator">15 * 8</gadget>
<output>120</output>

<result>120</result>