The school held a popular science knowledge competition. Xiao Ming has answered 30 questions correctly and 6 questions wrong. If he wants to make his correct answer rate reach 85%, how many questions must he answer correctly in a row?
学校举行科普知识比赛，小明已经答对了30道题，答错了6道题．如果他想使自己的答题正确率达到85%，那么还要连续答对多少道题．
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1 - (17/20)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">6 / (3/20)</gadget>
<output>40</output>

<gadget id="calculator">40 - 30 - 6</gadget>
<output>4</output>

<result>4</result>