The sixth-grade office bought a pack of white paper. It is planned to use 40 sheets per day, which can be used for 20 days. Because of saving paper, only 16 sheets are actually used per day. How many days can it actually be used for?
六年级办公室买来一包白纸，计划每天用40张，可以用20天，由于注意节约用纸，实际每天只用16张，实际可用多少天？
<gadget id="calculator">20 / 16</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">40 * (5/4)</gadget>
<output>50</output>

<result>50</result>