5 times a number minus the smallest composite number, the difference is 71. What is this number?
一个数的5倍减去最小的合数，差是71．这个数是多少？
<gadget id="calculator">71 + 4</gadget>
<output>75</output>

<gadget id="calculator">75 / 5</gadget>
<output>15</output>

<result>15</result>