How many multiples of 5 are there between 4000 and 7000 without repeating numbers?
在4000至7000内有多少个无重复数字的5的倍数．
<gadget id="calculator">3 * 8 * 7</gadget>
<output>168</output>

<gadget id="calculator">2 * 8 * 7</gadget>
<output>112</output>

<gadget id="calculator">168 + 112</gadget>
<output>280</output>

<result>280</result>