Kindergarten bought some fruits, took out (1/4) of the total and gave it to the big class, and took out (2/5) of the total to the middle class, leaving 7 kilograms. How many kilograms of fruit did the kindergarten buy in total?
幼儿园买来一些水果，取出总数的(1/4)分给大班，又取出总数的(2/5)分给中班，还剩7千克．幼儿园一共买来多少千克水果．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">7 / (7/20)</gadget>
<output>20</output>

<result>20</result>