The mass ratio of the two bags of sugar between A and B is 4:1. If 13 grams are taken out from bag A and put into bag B, the mass ratio of the two bags of sugar between A and B is 7:5. How many grams is the original packet of sugar?
甲、乙两包糖的质量比是4：1，如果从甲包取出13克放入乙包，甲、乙两包糖的质量比为7：5．甲包糖原来有多少克？
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

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

<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">(4/5) - (7/12)</gadget>
<output>13/60 = around 0.216667</output>

<gadget id="calculator">13 / (13/60)</gadget>
<output>60</output>

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

<result>48</result>