There are the same number of pencil cases in the boxes. If 30 pencil boxes are taken from each box, then the sum of the remaining pencil boxes in the 5 boxes is equal to the sum of the numbers in the original 2 boxes. Ask how many pencil cases are in each box?
箱里放着同样个数的铅笔盒，如果从每只箱里拿出30个，那么5只箱里剩下的铅笔盒的个数总和等于原来2只箱里个数的总和．问原来每只箱里有几个铅笔盒？
<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">5 / 3</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">30 * (5/3)</gadget>
<output>50</output>

<result>50</result>