Cut two colored ribbons with a length of 45 cm and a width of 30 cm into short ribbons of the same length without any residue. What is the longest length of each ribbon?
把两根分别长45厘米、宽30厘米的彩带剪成长度一样的短彩带且无剩余，每根彩带最长是多少厘米？
<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>