The first class planted 50 trees, which were planted by the second class (5/7). How many trees were planted by the two classes?
一班栽了50棵树，是二班栽的(5/7)，两个班一共栽了多少棵树？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">50 / (5/7)</gadget>
<output>70</output>

<gadget id="calculator">70 + 50</gadget>
<output>120</output>

<result>120</result>