The primary school holds an art competition, with a number of first, second and third prizes. First and second prizes accounted for (3/5) of the total number of awardees, second and third prizes accounted for (7/10) of the total number of awardees, second prizes accounted for what percentage of the total number of awardees ?
小学举办美术作品大赛，设一、二、三等奖若干名．获一、二等奖的占奖总人数的(3/5)，获二、三等奖的占获奖总人数的(7/10)，获二等奖的占获奖总人数的几分之几？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(7/10) - 1</gadget>
<output>-3/10 = around -0.3</output>

<gadget id="calculator">(3/5) + (-3/10)</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>