There are 450 pear trees in the orchard, and one apricot tree belongs to pear trees (3/5) and peach trees (6/7). How many peach trees are there in the orchard?
果园有梨树450棵，杏树的棵树是梨树的(3/5)，又是桃树的(6/7)，果园有桃树多少棵？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">(3/5) / (6/7)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">450 * (7/10)</gadget>
<output>315</output>

<result>315</result>