40 tons are transported away, and the rest is 16 tons less than the original (21/25), what is the original amount?
运走40吨，剩下的比原来的(21/25)少16吨，原来有多少．
<gadget id="calculator">40 - 16</gadget>
<output>24</output>

<gadget id="calculator">21 / 25</gadget>
<output>21/25 = around 0.84</output>

<gadget id="calculator">1 - (21/25)</gadget>
<output>4/25 = around 0.16</output>

<gadget id="calculator">24 / (4/25)</gadget>
<output>150</output>

<result>150</result>