Xiaoqiang's average score in the first and second tests of Mathematics is 85 points, and the average score of the three tests after the third test is 90 points. What is the score for the third test?
小强数学第一、二次测验的平均成绩是85分，第三次测验后三次的平均成绩是90分，第三次得多少分．
<gadget id="calculator">90 * 3</gadget>
<output>270</output>

<gadget id="calculator">85 * 2</gadget>
<output>170</output>

<gadget id="calculator">270 - 170</gadget>
<output>100</output>

<result>100</result>