batch of trees were planted in Hongxing Village, and the survival rate was 85%. There were 750 trees that did not survive. How many of these trees survived?
红星村种了一批树，成活率是85%，没成活的有750棵，这批树成活的有多少棵？
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1 - (17/20)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">750 / (3/20)</gadget>
<output>5_000</output>

<gadget id="calculator">5_000 - 750</gadget>
<output>4_250</output>

<result>4_250</result>