In a subtraction formula, the sum of the minuend, the subtrahend, and the difference is 120, and the ratio of the difference to the subtrahend is 1:4. What is the subtrahend?
在一道减法算式中，被减数、减数、差的和是120，差与减数比是1：4，减数是多少．
<gadget id="calculator">120 / 2</gadget>
<output>60</output>

<gadget id="calculator">1 + 4</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">60 * (4/5)</gadget>
<output>48</output>

<result>48</result>