A store can still make a profit of 20% by selling the goods at a discount of 10% off the listed price. The purchase price of the goods is 21 yuan. How much is the price of each item.
一个商店把货物按标价的9折出售，仍可获利20%，该货物的进价是21元．则每件货物的标价多少元．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">21 * (1/5)</gadget>
<output>21/5 = around 4.2</output>

<gadget id="calculator">21 + (21/5)</gadget>
<output>126/5 = around 25.2</output>

<gadget id="calculator">(126/5) / 0.9</gadget>
<output>28</output>

<result>28</result>