East Village planted 24 hectares of trees this year, and last year's tree planted area was this year's (7/8). How many hectares of trees were planted last year?
东村今年植树24公顷，去年植树的面积是今年的(7/8)．去年植树多少公顷？
<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">24 * (7/8)</gadget>
<output>21</output>

<result>21</result>