Zhang Hua, Zhao Min and Qian Yong went to the library on different days: Zhang Hua went every 4 days; Zhao Min went every 5 days; Qian Yong went every 6 days. The last time the three of them met on Sunday, how many days will it take for them to meet again?
张华、赵敏和钱勇三人隔不同的天数去图书馆一次：张华4天去一次；赵敏5天去一次；钱勇6天去一次．上次他们三人是星期天在相遇的，再过多少天他们才能再次相遇？
<gadget id="calculator">2 * 2 * 3 * 5</gadget>
<output>60</output>

<result>60</result>