There are two professional households, A and B. Last year, A’s annual income was three times that of B’s. A used (1/5) of the annual income to support the running of the school, and used (1/4) of the annual income to purchase scientific and technological books. If A gives B another 6,500 yuan, the remaining money of A will be equal to B's current money. Ask: How much was A's annual income last year?
甲、乙两个专业户，去年甲全年的收入是乙的3倍．甲用全年收入的(1/5)支援了办学，又用了全年收入的(1/4)购买了科技书刊．如果甲再给乙6500元，这样甲剩下的钱就和乙现在的钱相等了．求：甲去年的全年收入是多少元？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">1 - (1/3) - (1/5) - (1/4)</gadget>
<output>13/60 = around 0.216667</output>

<gadget id="calculator">2 / (13/60)</gadget>
<output>120/13 = around 9.230769</output>

<gadget id="calculator">6_500 * (120/13)</gadget>
<output>60_000</output>

<result>60_000</result>