There are 90 students in a knowledge competition in a certain school, of which 10 won the first prize, the poems that won the second prize are 1.5 times the first prize, and the rest are third prizes. How many people won the third prize?
某学校进行知识竞赛的同学共90人，其中获得一等奖的有10人，获得二等奖的诗一等奖的1.5倍，其余的是三等奖的．获三等奖的有多少人？
<gadget id="calculator">10 * 1.5</gadget>
<output>15</output>

<gadget id="calculator">90 - 10 - 15</gadget>
<output>65</output>

<result>65</result>