Both horse farms A and B raise red, white and black horses, of which red horses and white horses account for 36% and 34% of the total number of horses respectively. It is also known that red horses account for 40% of horse farms in A %, white horses account for 25%; red horses account for 30% in horse farm B, what percentage of black horses in horse farm B?
甲、乙两个养马场养的都是红、白、黑三种颜色的马，其中红马、白马数分别占养马总数的36%和34%，还知甲养马场中红马占40%，白马占25%；乙养马场中红马占30%，问乙养马场中黑马占百分之几？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">34 / 100</gadget>
<output>17/50 = around 0.34</output>

<gadget id="calculator">36 / 100</gadget>
<output>9/25 = around 0.36</output>

<gadget id="calculator">(9/25) - (3/10)</gadget>
<output>3/50 = around 0.06</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) - (9/25)</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">(3/50) / (1/25)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) * (17/50)</gadget>
<output>51/100 = around 0.51</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(3/2) * (1/4)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(51/100) - (3/8)</gadget>
<output>27/200 = around 0.135</output>

<gadget id="calculator">(17/50) + (27/200)</gadget>
<output>19/40 = around 0.475</output>

<gadget id="calculator">1 - (3/10) - (19/40)</gadget>
<output>9/40 = around 0.225</output>

<result>9/40 = around 0.225</result>