Xiaohong, Xiaohua and Xiaomei go to the stationery store to buy stationery together. Xiaohong bought 5 pens and 4 notebooks for 21.3 yuan, Xiaohua bought 4 pens and 5 notebooks for 21 yuan, and Xiaomei bought 6 pens and 6 notebooks.
小红、小华和小美一同到文具店买文具．小红买5支笔4个本子花了21.3元，小华买4支笔5个本子花了21元，小美买6支笔6个本子花多少元．
<gadget id="calculator">21.3 + 21</gadget>
<output>42.3</output>

<gadget id="calculator">42.3 / 9</gadget>
<output>4.7</output>

<gadget id="calculator">4.7 * 6</gadget>
<output>28.2</output>

<result>28.2</result>