It is known that (1/(a))+(1/(b))=1, (1/(a))+(1/(b))+(1/(c))=2.7, then c=what
已知(1/(a))+(1/(b))=1，(1/(a))+(1/(b))+(1/(c))=2.7，则c=多少
<gadget id="calculator">10 / 17</gadget>
<output>10/17 = around 0.588235</output>

<result>10/17 = around 0.588235</result>