Xu Li deposited the 100 yuan of pocket money he had saved in the bank. When it was due, he got a total of 105 yuan. How much was Xu Li's after-tax interest?
徐力将自己节约下来的零花钱100元存入银行，到期时，他共取得105元，徐力得到税后利息多少元．
<gadget id="calculator">105 - 100</gadget>
<output>5</output>

<result>5</result>