Xiaohong's father received a salary of 1,800 yuan this month. According to the tax law, personal income tax should be paid on the part of the monthly salary exceeding 1,100 yuan (5% tax rate for less than 500 yuan, 10% tax rate for 500-1000 yuan). According to regulations, how much personal income tax should Xiaohong's father pay this month?
小红的爸爸这月领得工资1800元．按照税法规定，每月工资超出1100元的部分应缴纳个人所得税(500元以内按5%的税率缴纳，500-1000元按10%的税率缴纳)．按照规定，小红的爸爸这月应缴纳个人所得税多少元？
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">500 * (1/20)</gadget>
<output>25</output>

<gadget id="calculator">1_800 - 1_100 - 500</gadget>
<output>200</output>

<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">200 * (1/10)</gadget>
<output>20</output>

<gadget id="calculator">25 + 20</gadget>
<output>45</output>

<result>45</result>