The sixth grade students of a certain school took two big and small cars to go on a spring outing. The students in the big car accounted for 55% of the whole grade, and 90 students got in the small car. Because there are many people in the small car, 10 people get off and go to the big car. At this time, what percentage of the whole grade is the number of people on the big car?
某校六年级学生分乘大小两辆汽车去春游，上大车的占全年级人数的55%，上小车的有90人．因为小车人多，下来10人到大车上去，这时大车上的人数占全年级的百分之几？
<gadget id="calculator">55 / 100</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">1 - (11/20)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">90 / (9/20)</gadget>
<output>200</output>

<gadget id="calculator">10 / 200</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(11/20) + (1/20)</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>