Dongfeng Primary School held a calligraphy competition, among which 15 people won the first prize, accounting for 1/8 of the total. The ratio of the number of people who won the second and third prizes was 2:5. How many people won the third prize?
东风小学举办书法比赛，其中有15人获得一等奖，占总数的(1/8)，获二、三等奖的人数比是2：5，有多少人获三等奖？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">15 / (1/8)</gadget>
<output>120</output>

<gadget id="calculator">120 - 15</gadget>
<output>105</output>

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

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

<gadget id="calculator">105 * (5/7)</gadget>
<output>75</output>

<result>75</result>