There are 15 roses in the school. The number of sweet-scented osmanthus is rose (2/3) and peony (2/7). How many peonies are there?
学校有月季花15棵，桂花的棵数是月季花的(2/3)，又是牡丹花的(2/7)，牡丹花有多少棵？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(2/3) / (2/7)</gadget>
<output>7/3 = around 2.333333</output>

<gadget id="calculator">15 * (7/3)</gadget>
<output>35</output>

<result>35</result>