The dividend is 320, the quotient is 15, and the remainder is 5. What is the divisor?
被除数是320，商是15，余数是5，除数是多少．
<gadget id="calculator">320 - 5</gadget>
<output>315</output>

<gadget id="calculator">315 / 15</gadget>
<output>21</output>

<result>21</result>