Four people, A, B, C, and D, buy stocks. A buys stocks that are 1/2 of the total amount purchased by the other three people. B buys stocks that are 1/3 of the total amount purchased by the other three people. C buys stocks It is (1/4) of the total purchases of the other three people. It is known that Ding bought 650,000 yuan of stock. Ask A, B, C, and D how much is the total amount of shares purchased by four people?
甲、乙、丙、丁四人购买股票，甲购买的股票是其他三人购买总数的(1/2)，乙购买的股票是其他三人购买总数的(1/3)，丙购买的股票是其他三人购买总数的(1/4)．已知丁购买了65万元的股票．问甲、乙、丙、丁四人共购买股票多少万元？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

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

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

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

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

<gadget id="calculator">65 / (13/60)</gadget>
<output>300</output>

<result>300</result>