The sum of the minuend, subtraction and difference is 200, the ratio of the subtrahend to the difference is 3:1, what is the subtrahend.
被减数、减、差的和是200，减数与差的比是3：1，减数是多少．
<gadget id="calculator">200 / 2</gadget>
<output>100</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">100 * (3/4)</gadget>
<output>75</output>

<result>75</result>