canteen bought 500kg of rice and 200kg of flour. After eating for a while, it was found that the amount of rice eaten was as much as that of flour, and the remaining rice was exactly 7 times the amount of flour left. Then how many kilograms of rice and flour are eaten respectively.
某食堂买来500千克的大米和200千克的面粉，吃了一段时间后，发现吃掉的大米和面粉同样多，而剩下的大米恰好是剩下面粉的7倍．则大米和面粉各吃掉多少千克．
<gadget id="calculator">200 * 7</gadget>
<output>1_400</output>

<gadget id="calculator">1_400 - 500</gadget>
<output>900</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">900 / 6</gadget>
<output>150</output>

<result>150</result>