The taxable amount is 40,000 yuan, and the tax payable is 4,200 yuan. What is the tax rate?
计税金额是40,000元，应交纳税额4,200元，税率是多少．
<gadget id="calculator">4_200 / 40_000</gadget>
<output>21/200 = around 0.105</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(21/200) * 1</gadget>
<output>21/200 = around 0.105</output>

<result>21/200 = around 0.105</result>