A batch of parts is divided equally between A and B for processing. The ratio of what A has processed to the rest is 2:1, and the ratio of B’s processed to the rest is 5:2. This batch of parts has been processed by a few points. How much?
一批零件，平均分给甲、乙两人加工，甲已加工的与剩下的比是2：1，乙已加工的与剩下的比是5：2，这批零件已加工了几分之几？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(1/2) * (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">(1/2) * (5/7)</gadget>
<output>5/14 = around 0.357143</output>

<gadget id="calculator">(1/3) + (5/14)</gadget>
<output>29/42 = around 0.690476</output>

<result>29/42 = around 0.690476</result>